Comtech EF Data CDM-750 Installation And Operation Manual
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Comtech EF Data CDM-750 Installation And Operation Manual

Advanced high-speed trunking modem
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CDM-750
Advanced High-Speed Trunking Modem
Installation and Operation Manual
For Firmware Version 1.3.1 or higher
IMPORTANT NOTE: The information contained in this document supersedes all previously published
information regarding this product. Product specifications are subject to change without prior notice.
Part Number MN-CDM750
Revision 1

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Summary of Contents for Comtech EF Data CDM-750

  • Page 1 CDM-750 Advanced High-Speed Trunking Modem Installation and Operation Manual For Firmware Version 1.3.1 or higher IMPORTANT NOTE: The information contained in this document supersedes all previously published information regarding this product. Product specifications are subject to change without prior notice.
  • Page 3 For Firmware Version 1.3.1 or higher Part Number MN-CDM750 Revision 1 December 7, 2010 Copyright © 2010 Comtech EF Data. All rights reserved. Printed in the USA. Comtech EF Data, 2114 West 7th Street, Tempe, Arizona 85281 USA, 480.333.2200, FAX: 480.333.2161...
  • Page 4 This page is intentionally blank.

  • Page 5: Table Of Contents

    Table of Contents TABLE OF CONTENTS ......................III  TABLES ............................XI  FIGURES ............................ XI  PREFACE ..........................XIII  About this Manual ........................... xiii  Reporting Comments or Suggestions Concerning this Manual ................xiii  Conventions and References ........................xiii  Metric Conversion ..............................xiii  Recommended Standard Designations ........................
  • Page 6 CDM-750 Advanced High-Speed Trunking Modem Revision 1 Table of Contents MN-CDM750 1.2  Functional Description ....................... 1–2  1.3  Features ............................1–3  1.3.1  Physical Description ..........................1–3  1.3.2  Major Assemblies ..........................1–4  1.3.2.1  Standard Assemblies ......................1–4  1.3.2.2  Optional Assemblies ......................1–4 ...
  • Page 7 LED Indicators ............................5–2  5.1.2  Keypad ..............................5–3  5.1.3  Vacuum Fluorescent Display (VFD) ....................5–3  5.2  CDM-750 Front Panel Menus ....................5–4  5.2.1  Opening Screen ............................. 5–4  5.2.2  Select: (Main) Menu ..........................5–5  5.2.2.1  Select: Configuration ......................5–6  5.2.2.1.1  CONFIG: Intf (Configure Interface) ................5–7 ...
  • Page 8 CDM-750 Advanced High-Speed Trunking Modem Revision 1 Table of Contents MN-CDM750 5.2.2.1.3.2  (CONFIG) Rx: Freq (Frequency) ............... 5–17  5.2.2.1.3.3  (CONFIG) Rx: Frame ..................5–17  5.2.2.1.3.4  (CONFIG) Rx: Mod (Modulation) ..............5–18  5.2.2.1.3.5  (CONFIG) Rx: Data ................... 5–18  5.2.2.1.3.6  (CONFIG) Rx: Pilot ................... 5–18 ...
  • Page 9 CDM-750 Advanced High-Speed Trunking Modem Revision 1 Table of Contents MN-CDM750 5.2.2.4.8  Info: Misc ........................5–40  5.2.2.4.9  Info: Remote ......................5–40  5.2.2.4.10  Info: Comp ......................5–41  5.2.2.5  Select: Store/Ld (Store/Load) ..................5–41  5.2.2.6  Select: Utility ........................5–41  5.2.2.6.1  Utility: Set-RTC ......................5–42 ...
  • Page 10 Long and Short Frames ........................7–9  7.4.5  Monotonic Operation .......................... 7–10  7.4.6  ModCod Selection ..........................7–11  7.5  Configuring ACM in the CDM-750 ..................7–13  7.5.1  ACM Configuration via the Front Panel ................... 7–15  7.6  Monitoring ACM Performance and Statistics ................ 7–15  7.7 ...
  • Page 11 CDM-750 Advanced High-Speed Trunking Modem Revision 1 Table of Contents MN-CDM750 8.4.1  DoubleTalk Carrier-in-Carrier Cancellation Process ................. 8–8  8.4.2  Margin Requirements ........................... 8–9  8.4.3  Carrier-in-Carrier Latency ........................8–9  8.4.4  Carrier-in-Carrier and Adaptive Coding and Modulation (ACM) ............ 8–9  8.4.5  Carrier-in-Carrier Link Design ......................8–10 ...
  • Page 12 CDM-750 Advanced High-Speed Trunking Modem Revision 1 Table of Contents MN-CDM750 11.3  G.703 E3/T3/STS-1 PIIC Connectors and Pinouts ..............11–3  11.4  Installing the G.703 E3/T3/STS-1 PIIC ................... 11–3  11.5  Summary of Specifications ....................... 11–4  11.5.1  General Specifications ........................11–4  11.5.2 ...
  • Page 13 Table 8-1. Spectral Efficiency using DoubleTalk Carrier-in-Carrier ............8–7 Table A-1. CDM-750 Co+No/No to C/N (Es/No) and Eb/No (dB) for DVB-S2 QPSK and 8PSK ..A–3 Table A-2. CDM-750 Co+No/No to C/N (Es/No) and Eb/No (dB) for DVB-S2 16APSK and 32APSK ..
  • Page 14 Figure 7-7. CDM-750 – ACM Congestion Control ................7–16 Figure 8-1. Conceptual Block Diagram ....................8–3 Figure 8-2. Conventional FDMA Link ..................... 8–5 Figure 8-3. Same Link Using CDM-750 and DoubleTalk Carrier-in-Carrier ........... 8–6 Figure 8-4. Duplex Link Optimization ..................... 8–6 Figure 8-5. DoubleTalk Carrier-in-Carrier Signals ................... 8–8 Figure 8-6.

  • Page 15: Preface

    PREFACE About this Manual This manual provides installation and operation information for the Comtech EF Data CDM-750 Advanced High-Speed Trunking Modem. This is a technical document intended for earth station engineers, technicians, and operators responsible for the operation and maintenance of the CDM-750.

  • Page 16: Cautions And Warnings

    FOR CONTINUED OPERATOR SAFETY, ALWAYS REPLACE THE FUSES WITH THE CORRECT TYPE AND RATING. CAUTION The CDM-750 is fitted with two fuses – one each for line and neutral connections. These are contained within the body of the IEC power inlet connector, behind a small plastic flap. •...

  • Page 17: International Symbols

    The equipment is not designed for connection to a power system that has no direct connection to ground. The CDM-750 is shipped with a line inlet cable suitable for use in the country of operation. If it is necessary to replace this cable, ensure the replacement has an equivalent specification. Examples of acceptable ratings for the cable include HAR, BASEC and HOXXX-X.

  • Page 18: Rohs Compliance

    This unit satisfies (with exemptions) the requirements specified in the European Union Directive on the Restriction of Hazardous Substances, Directive 2002/95/EC (EU RoHS). EMC (Electromagnetic Compatibility) Compliance In accordance with European Directive 2004/108/EEC, the CDM-750 has been shown, by independent testing, to comply with the following standards: Emissions: EN 55022 Class B - Limits and methods of measurement of radio interference characteristics of Information Technology Equipment.

  • Page 19: Warranty Policy

    The warranty does not apply to any part of a product that has been installed, altered, repaired, or misused in any way that, in the opinion of Comtech EF Data Corporation, would affect the reliability or detracts from the performance of any part of the product, or is damaged as the result of use in a way or with equipment that had not been previously approved by Comtech EF Data Corporation.

  • Page 20: Exclusive Remedies

    A fixed charge established for each product will be imposed for all equipment returned for warranty repair where Comtech EF Data Corporation cannot identify the cause of the reported failure.

  • Page 21: Customer Support

    Tempe, Arizona 85281 USA 480.333.2200 (Main Comtech EF Data number) 480.333.4357 (Customer Support Desk) 480.333.2161 FAX To return a Comtech EF Data product (in-warranty and out-of-warranty) for repair or replacement: • the Comtech EF Data Customer Support Department. Be prepared to supply the...
  • Page 22 CDM-750 Advanced High-Speed Trunking Modem Revision 1 Preface MN-CDM750 Notes:...

  • Page 23: Chapter 1. Introduction

    Overview Figure 1-1. CDM-750 Advanced High-Speed Trunking Modem The CDM-750 Advanced High-Speed Trunking Modem (Figure 1-1) is the ideal choice for network operators, enterprise users, and service providers demanding maximum throughput while using minimal satellite resources in point-to-point links. The CDM-750 combines potent DVB-S2 ®...

  • Page 24: Functional Description

    FAST (Fully Accessible System Topology) upgrade. The CDM-750 runs on an embedded operating system and does not have moving parts for media storage. This design provides carrier class reliability and high speed, purpose-driven processing.

  • Page 25: Features

    A similar process without GSE for non-IP data is used in the receive side for serial data, e.g., the G.703 interface. For DVB-S2: The CDM-750 supports DVB-S2 QPSK, 8PSK, 16APSK, and 32APSK modulation/ demodulation up to 63 Msps with receive data rates up to 169 Mbps depending on the modulation type and code rate.

  • Page 26: Major Assemblies

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Introduction MN-CDM750 1.3.2 Major Assemblies 1.3.2.1 Standard Assemblies Assembly Description Where Installed PL-0000571 Modem Card PL-0000612 Main Card (includes Ethernet Interfaces) In chassis (top cover access) PL-0000626 PIIC Motherboard Assembly KT-0000150 AC Power Supply for modem (not BUC) 1.3.2.2...

  • Page 27: Dimensional Envelope

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Introduction MN-CDM750 1.3.3 Dimensional Envelope Figure 1-2. CDM-750 Dimensional Envelope 1–5...

  • Page 28: Physical Features

    Front Panel Figure 1-3. CDM-750 Front Panel View Figure 1-3 shows the front panel of the CDM-750 High Speed Trunking Modem. The front panel features (from left) eight Light-Emitting-Diode (LED) indicators; a six-button keypad; and a Vacuum Fluorescent Display (VFD): •...

  • Page 29: Hardware Options

    SFP [Small Form Factor Pluggable] Module socket) provided at the CDM-750 rear panel. • The optional G.703 E3/T3/STS-1 (34.368/44.768/51.84 Mbps) interface(s) may be installed in the two PIIC (Plug-In Interface Card) slots provided at the CDM-750 rear panel. • Additional PIIC-compatible data interface options (e.g., ASI, OC3, HSSI, etc.) will become available with future releases.

  • Page 30: Flash Upgrading Modem Firmware

    If, at a later date, the user wishes to upgrade the functionality of a modem, Comtech EF Data provides Fully Accessible System Topology (FAST), which facilitates on-location upgrade of the operating feature set without removing a modem from the setup.

  • Page 31: Supporting Hardware And Software

    Hardware 1.3.10 Supporting Hardware and Software For 1:1 redundant applications, the CDM-750 Advanced High-Speed Trunking Modem is supported by the CRS-170A Redundancy Switch for L-Band operation, or the CRS-180 Redundancy Switch for 70/140 MHz operation. M:N redundancy support will be available in future releases.

  • Page 32: Summary Of Specifications

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Introduction MN-CDM750 Summary of Specifications 1.4.1 System Specifications Symbol/Date Rate Range Programmable in 1 sps increments DVB-S2 • QPSK: 1/2, 3/5, 2/3, 3/4, 4/5, 5/6, 8/9, 9/10 to 63 Msps / 112.6 Mbps max •...

  • Page 33: Base Unit Connectors

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Introduction MN-CDM750 1.4.3 Base Unit Connectors DB-15 male: Form C; Tx, Rx and unit faults; External Tx Carrier Off; IQ test point Alarm Connector • DB-9 male with EIA-232 and RS 485 2W/4W Unit Management •...

  • Page 34: Demodulator (Dual If)

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Introduction MN-CDM750 1.4.6 Demodulator (Dual IF) 70 / 140 MHz 50 to 180 MHz in 100 Hz steps Impedance / Connector 75 Ω / BNC Female. Return loss 15 dB min Input Power Desired Carrier = -58 + 10Log(Symbol Rate in Msps) dBm min and -18 dBm max –...

  • Page 35: Adaptive Coding And Modulation (Acm)

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Introduction MN-CDM750 Figure 1-6. L-Band Input Level vs Symbol Rate 1.4.7 Adaptive Coding and Modulation (ACM) Adaptive Coding and Modulation, using DVB-S2 QPSK, 8PSK, 16APSK, 32APSK with Normal System type Frames: Total of 25 ModCods (QPSK 1/4, 1/3 and 2/5 are excluded)

  • Page 36: Doubletalk Carrier-In-Carrier (Cnc)

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Introduction MN-CDM750 ® 1.4.8 DoubleTalk Carrier-in-Carrier (CnC) Operating Mode Requires the two carriers in a duplex circuit to share a common frequency. Different symbol rates are allowed. CnC Ratio Ratio of Interferer Carrier Power to Desired Carrier Power (in dB). Positive values represent a stronger Interferer Carrier, and negative values represent a stronger Desired Carrier.

  • Page 37: Chapter 2. Installation

    Chapter 2. INSTALLATION Unpacking and Inspection The CDM-750 Advanced High-Speed Trunking Modem and its Installation and Operation Manual are packaged in a pre-formed, reusable, cardboard carton containing foam spacing for maximum shipping protection. Be sure to keep all shipping materials for the carrier's inspection.

  • Page 38: Mounting

    MN-CDM750 Mounting If the CDM-750 is to be mounted in a rack, ensure that there is adequate clearance for ventilation, particularly at the sides. In rack system where there is high heat dissipation, forced air-cooling must be provided by top or bottom mounted fans or blowers. Under no circumstance should the highest internal rack temperature be allowed to exceed 50°C (122°F).

  • Page 39: Method B: Optional Bearingless Side-Railing Set (Fp/Sl0006)

    If the converter is to be mounted on slides, install an optional bearingless rack slide set into the rack cabinet and onto the sides of the CDM-750 using the hardware provided with the slide set: Per Figure 2-2, install the CEFD P/N FPSL0006 optional bearingless rack slide sets as follows:...

  • Page 40: Figure 2-2. Optional Bearingless Side-Railing Set (Fp/Sl0006) Installation

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Installation MN-CDM750 Optional Side-Railing Set FP/SL0006 CEFD Part Number Description FP/SL0006 Bearingless Side-Railing Set Figure 2-2. Optional Bearingless Side-Railing Set (FP/SL0006) Installation 2–4...

  • Page 41: Figure 3-1. Cdm-750 Rear Panel Views

    PINOUTS Connector Overview The CDM-750 Advanced High-Speed Trunking Modem rear panel connectors, shown in Figure 3-1, provide all necessary external connections between the modem and other equipment. Table 3-1 on the next page summarizes the connectors provided on the rear panel interface, grouped according to service function.

  • Page 42: Chapter 3.  Rear Panel Connectors And Pinouts

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Rear Panel Connectors and Pinouts MN-CDM750 Table 3-1. CDM-750 Rear Panel Connectors Connector Group Name Connector Type Function (Chapter 3 Sect. Ref.) L-BAND RX IN Type ’N’ female IF Input (Sect. 3.2) IF RX IN...

  • Page 43: If Connections

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Rear Panel Connectors and Pinouts MN-CDM750 IF Connections   There may be DC voltages present on the Type ‘N’ Rx and Tx connectors, up to a maximum of 48 volts. CA UTIO N 3.2.1...

  • Page 44: Utility Connections

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Rear Panel Connectors and Pinouts MN-CDM750 Utility Connections 3.3.1 J1 | ALARM Connector, DB-15M The J1 | ALARM connector provides the unit alarms interface via a 15-pin Type ‘D’ male connector. The connector pinouts are as follows:...

  • Page 45: J3 | Remote Connector, Db-9M

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Rear Panel Connectors and Pinouts MN-CDM750 3.3.3 J3 | REMOTE Connector, DB-9M The J3 | REMOTE connector provides the remote control interface via a 9-pin Type ‘D’ male connector. It is intended for connection to an M&C computer or terminal device, and is user selectable for either EIA-232 or EIA-485.

  • Page 46: J8 | Ext Ref Connector, Bnc

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Rear Panel Connectors and Pinouts MN-CDM750 3.3.5 J8 | EXT REF Connector, BNC The J8 | EXT REF (External Reference) input/output is a female BNC connector used to supply a master reference to the entire chassis. The internal 10 MHz reference is phase locked to this input, if selected.

  • Page 47: Terrestrial Data Connections

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Rear Panel Connectors and Pinouts MN-CDM750 Terrestrial Data Connections 3.4.1 J5 | DATA, J6 | DATA Connections, RJ-45F It is strongly suggested that the user does NOT mix products of different speeds (e.g., 10BaseT on J5, 100BaseT on J6, and GigE on J7), or different duplex operation (e.g., half duplex on J5 and full...

  • Page 48: J7 | Optical Connection, 1000Base-Sx Cage

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Rear Panel Connectors and Pinouts MN-CDM750 3.4.2 J7 | OPTICAL Connection, 1000Base-SX Cage It is strongly suggested that the user does NOT mix products of different speeds (e.g., 10BaseT on J5, 100BaseT on J6, and GigE on J7), or different duplex operation (e.g., half duplex on J5 and full...

  • Page 49: Piic Data Interfaces

    G.703 E3/T3 PIIC Data Interface The G.703 E3/T3 PIIC module plugs into either of the available interface option slots provided at the CDM-750 rear panel. For more information about this optional interface, refer to Chapter 11. G.703 PIIC E3/T3 INTERFACE. Note the following:...

  • Page 50: Power / Ground Connections

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Rear Panel Connectors and Pinouts MN-CDM750 Power / Ground Connections 3.5.1 Alternating Current Power Connector A standard, detachable, non-locking, 3-prong power cord (IEC plug) supplies the Alternating Current (AC) power to the modem via this connector.

  • Page 51: Chapter 4. Flash Upgrading

    New firmware can be downloaded via the Internet to an external PC. • The upgrade can be performed without opening the CDM-750 by simply connecting the unit to an Ethernet port of the external PC. The firmware update is then transferred via File Transfer Protocol (FTP) from the external PC to the CDM-750.

  • Page 52: Ethernet Ftp Upload Procedure

    Revision 1 Flash Upgrading MN-CDM750 Ethernet FTP Upload Procedure Follow the steps provided in this section. Once the upload is complete, the CDM-750’s top-level display screen will appear (for more information, see Chapter 5. FRONT PANEL OPERATION). Step Procedure Identify the reflashable product, firmware number, and version for download: The current base modem M&C version can be viewed at the top level display on the CDM-...
  • Page 53 Step 2, then use the “dir” command to list the files extracted from the downloaded archive file. Connect the external PC to the CDM-750 10/100 Ethernet Management Port via a hub or a switch, or directly to a PC. Send a “ping” command to the CDM-750 to verify the connection and communication: First, determine the IP address of the CDM-750 remotely or by using the front panel: •...
  • Page 54 Terminate the FTP session by typing "bye" and closing Command-line. c) Verify that the new file loaded using the procedure in Step 1. d) Change the desired image to boot from the CDM-750 font panel menu: SELECT: Select; use the up or down arrows (▲▼) on the front...

  • Page 55: Chapter 5. Front Panel Operation

    Figure 5-1 identifies the key features of the CDM-750 Advanced High-Speed Trunking Modem’s front panel. The front panel is used to fully control and monitor the CDM-750’s operation. The front panel features (from left) eight Light-Emitting Diode (LED) Indicators, a six-button keypad, and a Vacuum Fluorescent Display (VFD).

  • Page 56: Led Indicators

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Front Panel Operation MN-CDM750 5.1.1 LED Indicators In general, the Alarm relay state will reflect the state of the Front Panel LEDs. For instance, if the Unit Status LED is red, the Unit Alarm relay will be active, etc. The one exception is the Transmit Traffic relay.

  • Page 57: Keypad

    (Up, Down) the user. 5.1.3 Vacuum Fluorescent Display (VFD) The CDM-750 features a Vacuum Fluorescent Display (VFD). The VFD is an active display showing two lines of 40 characters each. It produces a blue light, the brightness of which can be controlled by the user. Compared to a Liquid Crystal Display (LCD), it has greatly superior viewing characteristics and does not suffer problems of viewing angle or contrast.

  • Page 58: Front Panel Menus

    Detailed information for options nested within the submenus is, in turn documented in those subsections. Table 5-1. CDM-750 Front Panel Menu Matrix Menu Branch / Submenu Sect.

  • Page 59: Select: (Main) Menu

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Front Panel Operation MN-CDM750 5.2.2 Select: (Main) Menu Select: Configuration Test Monitor Info Store/Ld Utility FAST The Select: (main) menu provides user access to all modem configuration, monitor and control menu branches. The table that follows identifies the functional description/overview for each menu branch. Refer to the chapter section for detailed information about the operations provided therein.

  • Page 60: Select: Configuration

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Front Panel Operation MN-CDM750 5.2.2.1 Select: Configuration CONFIG: Intf Clocks Misc Mask Remote IP Comp The submenus available from the Configuration menu branch are as follows: CONFIG Sect. Description Submenu Used to configure the operating status of the installed optional Plug-in Interface Intf 5.2.2.1.1...

  • Page 61: Config: Intf (Configure Interface)

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Front Panel Operation MN-CDM750 5.2.2.1.1 CONFIG: Intf (Configure Interface) Note: The number of available selections depends on the installed interfaces. When an optional Plug-In Interface Card (PIIC) is installed in Interface Slot 1 or Interface Slot 2, the name of the...
  • Page 62 CDM-750 Advanced High-Speed Trunking Modem Revision 1 Front Panel Operation MN-CDM750 (CONFIG: INTF) PIICX ClkSource ExtClock ExtClock: 1 MHz To set the expected clock rate for the external clock source located on the J8 | Ext Ref BNC connector: Use the ▲ ▼ arrow keys to select 1 MHz, 2 MHz, 5 MHz, 10 MHz, 20 MHz, 34.368 MHz (E3), 44.736 MHz (T3), or 51.840 MHz (STS1), and then press...
  • Page 63 CDM-750 Advanced High-Speed Trunking Modem Revision 1 Front Panel Operation MN-CDM750 (CONFIG: INTF) PIICX RxBuffer Recenter Rx Buffer: ReCenter If the RxBuffer Fill Status is dropping (approaching 0%), the Rx traffic is not keeping up with the RxClock setting and a data underflow is occurring. If the RxBuffer Fill Status is increasing (approaching 100%), the Rx traffic is coming in faster than the RxClock setting and a data overflow is occurring.

  • Page 64: Config) Intf: Gbeix

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Front Panel Operation MN-CDM750 Note the following: Mask Type Description Redundancy Switchover and Tx Mute Alarm Alarms can be viewed from the Monitor: Live An alarm WILL NOT cause a redundancy switch Alarms menu (Sect. 5.2.2.3.1). Alarms cause and WILL NOT mute the Tx carrier the Unit Status LED to turn AMBER.

  • Page 65: Config) Intf: Optinst

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Front Panel Operation MN-CDM750 (CONFIG: INTF) GBEX FlowControl Flow Control: Disabled Applies To All Ports The use of Flow Control or Pause Frames is useful when ALL devices connected to the modems are set to honor Pause frames. When used properly, Flow Control can act as a traffic valve in an ACM environment.

  • Page 66: Config: Tx

    • The default Txα setting is .20 (20%). When the CDM-750 is in CnC (Carrier-in-Carrier) mode, the modem itself will determine the Tx spectral inversion. The operator will not have control of spectral inversion selection while CnC mode is ON and any changes to this field will be rejected.

  • Page 67: Config) Tx: Power

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Front Panel Operation MN-CDM750 5.2.2.1.2.3 (CONFIG) Tx: Power Output Power Level= –20.0 dBm To configure the Tx Output Power Level: First, use the ◄ ► arrow keys to select a digit to edit, and then use the arrow keys to edit the value of that digit.
  • Page 68 CDM-750 Advanced High-Speed Trunking Modem Revision 1 Front Panel Operation MN-CDM750 (CONFIG) Tx: Data Tx Data Rate Tx Data Rate = 070000.000 kbps To configure the Tx Data Rate: First, use the arrow keys to select a digit to edit, and then ▲...

  • Page 69: Config) Tx: Pilot

    Use the ▲ ▼ arrow keys to select Pilot Location as Average or Peak, and then press ENTER. Note the following: • The CDM-750 automatically adjusts, but the default value is Average. • Select Average to set the pilots and header to the average power band of the transmitted constellation (QPSK, 8PSK, 16APSK or 32APSK) per DVB-S2 (required for ACM –...

  • Page 70: Table 5-2. Symbol Rate / Data Rate Range For Standard Fecframe (Dvb-S2 Standard Fecframe = 64,800 Bits)

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Front Panel Operation MN-CDM750 Table 5-2. Symbol Rate / Data Rate Range for Standard FECFrame (DVB-S2 Standard FECFrame = 64,800 bits) Symbol Rate Data Rate (Mbps) Data Rate (Mbps) Inner Spectral Spectral MODCOD...

  • Page 71: Config: Rx

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Front Panel Operation MN-CDM750 5.2.2.1.3 CONFIG: Rx Rx:IF Freq Frame Mod Data Pilot EsNo Data 130706.252kbps 030000.000ksps( On the top line: Use the ◄ ► arrow keys to select IF, Freq, Frame, Mod, Data, Pilot, or EsNo, and then press ENTER.

  • Page 72: Config) Rx: Mod (Modulation)

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Front Panel Operation MN-CDM750 5.2.2.1.3.4 (CONFIG) Rx: Mod (Modulation) MODCOD=QPSK 1/2 Read Only This read-only screen identifies the active modulation type. Press ENTER or CLEAR to return to the previous menu. 5.2.2.1.3.5 (CONFIG) Rx: Data...

  • Page 73: Config) Rx: Esno

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Front Panel Operation MN-CDM750 5.2.2.1.3.7 (CONFIG) Rx: EsNo Receive EsNo Alarm Point = 02.0 dB To edit the EsNo Alarm Point: First, use the ◄ ► arrow keys to select a digit to edit, and then use arrows keys to edit the value of that digit.

  • Page 74: Config: Acm (Adaptive Coding And Modulation)

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Front Panel Operation MN-CDM750 With the Internal 10 MHz Reference selected, very fine adjustment of the Internal 10 MHz Reference is possible. The adjustment value is retained in EEPROM memory, and is therefore not lost when the NVRAM is cleared.

  • Page 75: Config) Acm Config: Unlock-Action

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Front Panel Operation MN-CDM750 5.2.2.1.5.2 (CONFIG) ACM Config: Unlock-Action When distant-end demod loses lock: Go to min Tx ModCod (Maintain,Min) Use this submenu to establish the desired action when the remote demod loses lock. This is important, as the ACM system depends on the feedback of the SNR metric from the remote demod to determine the optimum ModCod.

  • Page 76: Config) Acm Config: Degradation

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Front Panel Operation MN-CDM750 5.2.2.1.5.4 (CONFIG) ACM Config: Degradation Degradation: QPSK=0.0 8PSK=0.0 16QAM=1.0 32APSK=2.0 An additional level of signal margin can be added to the QEF switch points in ACM operation by adding a degradation figure per modulation type. This degradation figure further increases the Es/No required to switch to a ModCod having a degradation figure above 0.0.

  • Page 77: Config) Carrier-In-Carrier: Search-Delay

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Front Panel Operation MN-CDM750 5.2.2.1.6.2 (CONFIG) Carrier-in-Carrier: Search-Delay CnC Search Delay: (range 0-300ms) Min: 010 ms Max: 290 ms (34v) To reduce the time taken for the CnC algorithm to converge, the user can restrict the range of delay the search uses.

  • Page 78: Config: Remote (Remote Control)

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Front Panel Operation MN-CDM750 For the Reference and DeCompInv masking option selections, Alarm, Fault, and Mask (as previously described), plus an addition masking option, are available: Mask Type Description Fault-Tx On Faults can be viewed in the Stored Events Log (Sect. 5.2.2.3.2). Faults cause: •...

  • Page 79: Config) Remote Control: Inband

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Front Panel Operation MN-CDM750 5.2.2.1.8.2 (CONFIG) Remote Control: Inband Enable Inband Modem Control: Enable Inband Modem Control allows remote Ethernet access via the Gigabit Ethernet data interfaces. Use the arrow keys to Enable or Disable this feature, and then press ENTER.

  • Page 80: Config) Ip Config: Snmp

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Front Panel Operation MN-CDM750 (CONFIG) IP Config: Addresses Gateway Ethernet IP Gateway: 192.168.001.002 The Gateway Address is the default next hop address used by the M&C to send traffic to when the M&C is sending a datagram to an IP address outside of its subnet mask or Address/Range.
  • Page 81 CDM-750 Advanced High-Speed Trunking Modem Revision 1 Front Panel Operation MN-CDM750 (CONFIG) IP Config: SNMP Communities Write SNMP Write Community: Private (20 chars) ( To edit the SNMP Write Community string: First, use the ◄ ► arrow keys to select the alphanumeric character to edit, and then use the arrow keys to edit that character.

  • Page 82: Config: Comp

    • Decompression enables or disables the Rx decompression path (Satellite to LAN). The decompression setting must match the far side CDM-750 Tx compression setting. A mismatch will cause all data to be dropped. Rx decompression does not require a software license or FAST Access Code; Rx decompression will work at all data rates regardless of the Tx compression license purchased.

  • Page 83: Select: Test

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Front Panel Operation MN-CDM750 5.2.2.2 Select: Test TEST: Mode BERT Comp (34) ◄ ► Use the arrow keys to select Mode, BERT, or Comp, and then press ENTER. 5.2.2.2.1 TEST: Mode Modem Test Mode = Normal (Norm,Tx-CW,DSB,SSB,IQ PN, F,IF Dig, /0) Per the following table, use the ▲...

  • Page 84: Figure 5-2. Loopback Test Modes

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Front Panel Operation MN-CDM750 Figure 5-2. Loopback Test Modes 5–30...

  • Page 85: Test: Bert Config

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Front Panel Operation MN-CDM750 5.2.2.2.2 TEST: BERT BERT: Config Monitor (34) Use the ◄ ► arrow keys to select Config or Monitor, and then press ENTER. 5.2.2.2.2.1 TEST: BERT Config BERT Tx:On BERT Pattern:...

  • Page 86: Select: Monitor

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Front Panel Operation MN-CDM750 5.2.2.3 Select: Monitor Monitor: Live-Alarms Stored-Events ACM Rx-Params Stats Buffer (34) ◄ ► Use the arrow keys to select Live-Alarms, Stored-Events, ACM, Rx-Params, CnC, or StatsP, and then press ENTER 5.2.2.3.1...

  • Page 87: Monitor: Stored-Events

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Front Panel Operation MN-CDM750 5.2.2.3.2 Monitor: Stored-Events Stored Events: Clear-All: No (No,Yes) #199 FT- Frame Sync 25/10/10 16:25:24 ◄ ► An example of a Stored Events screen is shown here. Use the arrow keys to navigate to the bottom line, and then use the arrow keys to browse through the available event log entries.

  • Page 88: Monitor: Cnc (Carrier-In-Carrier Parameters)

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Front Panel Operation MN-CDM750 Rx-Params: EsNo=>23.5 dB ⌂F=+005.0 BER=9.4E-07 ModCod:18 RxLevel=-31dBm Note the following: Item Description This shows the value of the Es/No calculated by the demodulator. Es/No is the energy per Symbol received (Es) divided by the noise spectral density (No).
  • Page 89 CDM-750 Advanced High-Speed Trunking Modem Revision 1 Front Panel Operation MN-CDM750 5.2.2.3.6.1 Monitor: Stats IPstats: WAN Total Last10s (34v) Bytes to WAN 0.0E+00 0.0E+00 Clr:N Typical for each display, the tally of Bytes or Packets sent/received is presented in scientific notation in two columns –...
  • Page 90 CDM-750 Advanced High-Speed Trunking Modem Revision 1 Front Panel Operation MN-CDM750 Use the ▲ ▼ arrow keys to select Y or N, and then either press ENTER (to wipe the buffer) or press CLEAR (to back out of the command and return to the previous menu).
  • Page 91 CDM-750 Advanced High-Speed Trunking Modem Revision 1 Front Panel Operation MN-CDM750 After viewing the desired statistics screen(s), should it be desired to clear the statistics buffer and re-initialize this screen, use the ◄ ► arrow keys on the bottom line to navigate to the Clr: setting.

  • Page 92: Monitor: Buffer

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Front Panel Operation MN-CDM750 After viewing the desired statistics screen(s), should it be desired to clear the statistics buffer and re-initialize this screen: Use the ▲ ▼ arrow keys select the CLR: setting as Y or N (the cursor position defaults to the CLR: setting on the on the bottom line);...

  • Page 93: Info: Tx

    (OptInst: will display Y for Yes, N for No – see Sec. 3.4.2 for further information on this interface). Press ENTER or CLEAR to return to the previous menu. Note: All interfaces are provided on the rear panel of the CDM-750. See Chapter 3. REAR PINOUTS for detailed information about these interfaces.

  • Page 94: Info: Clocks

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Front Panel Operation MN-CDM750 5.2.2.4.5 Info: Clocks REF = Internal + O/P The Reference is displayed here. Press ENTER or CLEAR to return to the previous menu. 5.2.2.4.6 Info: ACM Tx ModCod=QPSK 3/4 RemEsNo:+21.9 dB...

  • Page 95: Info: Comp

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Front Panel Operation MN-CDM750 5.2.2.4.10 Info: Comp Comp=Disabled DeComp=Disabled This screen displays the operational status for the optional K4 GZip lossless compression and decompression as either Enabled or Disabled. Press ENTER or CLEAR to return to the previous menu.

  • Page 96: Utility: Set-Rtc

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Front Panel Operation MN-CDM750 5.2.2.6.1 Utility: Set-RTC Edit Real-Time Clock: Time: 12:01:02 Date:26/10/06 (34v) To edit the time and date settings of the Real-Time Clock: First, use the ◄ ► arrow keys to select a digit to edit, and then use the arrow keys to edit the value of the digit.

  • Page 97: Utility: Circuit Id

    DATA CUSTOMER SUPPORT. IMPORTANT These submenus permit the user to view information about the CDM-750 internal firmware. The modem can store two complete firmware images, and the user can select which image is loaded the next time the unit reboots.

  • Page 98: Utility) Firmware Images: Select

    FAST (Fully Accessible System Topology) provides the means to enable new options in the modem. Contact Comtech EF Data during normal business hours to obtain the FAST Access Code for the desired option. For more information about enabling FAST options, see Appendix C.

  • Page 99: Fast) Fast Options: Set

    To enable new FAST options in the modem, the user must first obtain the FAST Access Code for the new option from Comtech EF Data Customer Support. Once obtained, the FAST Access Code must be entered carefully. First, use the ◄...

  • Page 100: Fast: Cnc

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Front Panel Operation MN-CDM750 5.2.2.7.3 FAST: CnC FractionalCnC:1-YearCounter=00000000 sec 90-DayCounter= 0000000 sec When Fractional CnC Mode is ordered, this screen displays the number of seconds remaining for both the 1-year (top line) and 90-day (bottom line) activation timers.

  • Page 101: Chapter 6. Ethernet Management

    Ethernet Management Interface Protocols The modem’s J4 | MGMT port, located on the rear panel of the CDM-750, is a 10/100 BaseT Ethernet Management Interface that supports three (3) management protocols: •...

  • Page 102: Snmp Community Strings

    MN-CDM750 The following MIB files are associated with the CDM-750: MIB File/Name Description FW10874-2-.mib ComtechEFData MIB file gives the root tree for ALL Comtech EF Data products and consists of only the following OID: ComtechEFData Root MIB file Name: comtechEFData Type: MODULE-IDENTITY OID: 1.3.6.1.4.1.6247...

  • Page 103: Telnet Interface

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Ethernet Management MN-CDM750 The following are the modem-supported MIB2 SNMPv1traps / SNMPv2 notifications: MIB2 SNMPv1 trap: Authentication Failure MIB2 SNMPv2 notifications: Authentication Failure 1.3.6.1.6.3.1.1.5.5 The following tables show the modem-supported Alarms and Faults SNMPv1 traps / SNMPv2...
  • Page 104 CDM-750 Advanced High-Speed Trunking Modem Revision 1 Ethernet Management MN-CDM750 Once logged into the Telnet interface as Administrator, the user can access the standard remote control interface defined Appendix D. REMOTE CONTROL, as per the example shown to the right: There is a disadvantage when using Windows DOS as Telnet Client.

  • Page 105: Web Server (Http) Interface

    The embedded Web Server (HTTP) Interface provides an easy to use interface for configuration, monitoring and control of all aspects of the CDM-750. These Web pages have been designed for optimal performance when using Microsoft’s Internet Explorer Version 5.5 or higher (the examples shown use Internet Explorer Version 7.0).

  • Page 106: Interface Menu Tree

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Ethernet Management MN-CDM750 Once the valid User Name and Password are accepted, user will CDM-750 Server Interface “splash” page, as per the example shown to the right: 6.5.3 Interface Menu Tree The menu tree illustrates the Web pages available via this interface:...

  • Page 107: Web Server Interface

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Ethernet Management MN-CDM750 6.5.4 Web Server Interface – Page Descriptions 6.5.4.1 Home pages Click the Home, Contact, or Support tab to continue. 6.5.4.1.1 Home | Home Figure 6-1. CDM-750 Home page From any location within the Web Server Interface, the user can select the Home top-level navigation tab and/or the nested Home tab to return back to this top-level page.

  • Page 108: Home | Contact

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Ethernet Management MN-CDM750 6.5.4.1.2 Home | Contact Figure 6-2. Home | Contact Information page The ‘Home | Contact’ page (Figure 6-2) provides basic contact information to reach Comtech EF Data Sales and Customer Support via phone, fax, or e-mail hyperlinks.

  • Page 109: Home | Support

    Figure 6-3. Home | Customer Support page The ‘Home | Support’ page (Figure 6-3) uses SMTP (Simple Mail Transport Protocol) to submit questions about or report problems with the CDM-750 to Comtech EF Data Modem Support (cdmipsupport@comtechefdata.com). The user should type in the pertinent contact information – Name, Company, Telephone, and E-mail address –...

  • Page 110: Admin (Administration)

    Figure 6-4. Admin | Access page The ‘Admin | Access’ page (Figure 6-4) provides the means to set up user names, passwords, the e-mail server, and the host IP addresses to facilitate communication with the CDM-750 Web Server Interface. System Account Access Information •...
  • Page 111 CDM-750 Advanced High-Speed Trunking Modem Revision 1 Ethernet Management MN-CDM750 • SMTP Server: Specify the mail server IP address from where you want to send the e-mail. • SMTP Domain Name / Destination: The Administrator can assign the SMTP Domain Name and Destination.

  • Page 112: Admin | Snmp

    Figure 6-5. Admin | SNMP page The ‘Admin | SNMP’ page (Figure 6-5) sets and returns administration information for the CDM-750 Simple Network Management Protocol (SNMP) feature. The Administrator can assign up to two SNMP Trap IP addresses. The Administrator can assign a SNMP Trap Community String. The factory default for this parameter is public.

  • Page 113: Configuration

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Ethernet Management MN-CDM750 6.5.4.3 Configuration pages The ‘Configuration’ pages are used to configure all modem parameters. Click the Modem or Utilities tab to continue. 6.5.4.3.1 Configuration | Modem Figure 6-6. Configuration | Modem page The ‘Configuration | Modem’...

  • Page 114: Configuration | Utilities

    6.5.4.3.2 Configuration | Utilities Figure 6-7. Configuration | Utilities page The ‘Configuration | Utilities’ page (Figure 6-7) is used to configure the following CDM-750 utility functions: Unit Use the drop-down menu to select the desired Test Mode. When done, click [Submit] as needed to execute this change.
  • Page 115 CDM-750 Advanced High-Speed Trunking Modem Revision 1 Ethernet Management MN-CDM750 Circuit ID The user may enter a Circuit ID string of up to 40 characters. Once the desired string is created here, click [Submit] as needed to save this change.

  • Page 116: Status

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Ethernet Management MN-CDM750 Save / Load This section allows the user to save, then load (recall) up to 10 configuration sets. The status of each slot is identified as either having a stored configuration set slot (Yes) or an empty slot (No).

  • Page 117: Status | Logs

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Ethernet Management MN-CDM750 6.5.4.4.2 Status | Logs Figure 6-9. Status | Logs page The ‘Status | Logs’ page (Figure 6-9) provides control over how faults, alarms, and stored statistics are processed by the unit. The user is also able to configure Alarm Masks for the unit with this page.

  • Page 118: Status | Info

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Ethernet Management MN-CDM750 6.5.4.4.3 Status | Info Figure 6-10. Status | Info page The read-only ‘Status | Info’ page (Figure 6-10), which updates automatically every 10 seconds, provides identifying information about the modem in its current configuration, including: •...

  • Page 119: Status | Firmware

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Ethernet Management MN-CDM750 6.5.4.4.4 Status | Firmware Figure 6-11. Status | Firmware Info page The read-only ‘Status | Firmware Info’ page (Figure 6-11) provides status windows pertaining to the unit’s operational firmware loads: •...

  • Page 120: Status | Acm

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Ethernet Management MN-CDM750 6.5.4.4.5 Status | ACM Figure 6-12. Status | ACM Status page The read-only ‘Status | ACM Status’ page (Figure 6-12) page is used to view ACM operating statistics. For more information pertaining to the data provided here, refer to Chapter 5. FRONT PANEL OPERATION or Chapter 7.

  • Page 121: Status | Ip Statistics

    IP operating statistics as processed via the GIGE1 (J5 | DATA), GIGE2 (J6 | DATA), Optical (J7 | OPTICAL), and Monitor and Control (J4 | MGMT) ports located on the CDM-750 rear panel. Statistics pertaining to the WAN interface, and K4 GZip Lossless Compression / Decompression are also provided.

  • Page 122: Status | Bb Statistics

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Ethernet Management MN-CDM750 6.5.4.4.7 Status | BB Statistics Figure 6-14. Status | BB Statistics page The read-only ‘Status | BB Statistics’ page (Figure 6-14) is used to view Modem Baseband operating statistics. Refer to Chapter 5. FRONT PANEL OPERATION for detailed information about the statistics provided on this page.

  • Page 123: Interfaces Page

    The ‘Interfaces’ page (Figure 6-15) is used to configure the optional G.703 Plug-In-Interface- Card(s) (PIICs) installed in PIIC slots 1 and 2 (located on the CDM-750 rear panel). Typical for the Slot1 and Slot2 page sections, when a G.703 PIIC is present in either or both slots: G.703...
  • Page 124 External Clock Source: Use the drop-down menu to set the expected clock rate for the external Clock source located on the J8 | EXT REF connector provided on the CDM-750 rear panel as 1 MHz, 2 MHz, 5 MHz, 10 MHz, 20 MHz, 34.368 MHz, 44.736 MHz, or 51.85 MHz.

  • Page 125: Txgraph Pages (Minutes / Hours / Days)

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Ethernet Management MN-CDM750 6.5.4.6 TxGraph pages (Minutes / Hours / Days) Figure 6-16. TxGraph pages (TxHours page shown) 6–25...
  • Page 126 CDM-750 Advanced High-Speed Trunking Modem Revision 1 Ethernet Management MN-CDM750 When the presence of the optional K4 GZip Compression is detected, the ‘TxGraph’ pages provide a live graphical representation of the trending characteristics that are available while using this feature.
  • Page 127 CDM-750 Advanced High-Speed Trunking Modem Revision 1 Ethernet Management MN-CDM750 Note that the Remote Es/No is the “reported” Es/No of the far end modem as seen by the local modem. This reported Remote Es/No data can be 250ms to 400ms old as this is the amount of time it can take for this data to traverse the satellite link for processing by the local modem.

  • Page 128: Rxgraph Pages (Minutes / Hours / Days)

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Ethernet Management MN-CDM750 6.5.4.7 RxGraph pages (Minutes / Hours / Days) Figure 6-17. RxGraph pages (RxHours page shown) 6–28...
  • Page 129 CDM-750 Advanced High-Speed Trunking Modem Revision 1 Ethernet Management MN-CDM750 When the presence of the optional K4 GZip Compression is detected, the ‘RxGraph’ pages provide a live graphical representation of the trending characteristics that are available while using this feature.
  • Page 130 CDM-750 Advanced High-Speed Trunking Modem Revision 1 Ethernet Management MN-CDM750 • Rx Capacity Configuration Parameters – This is a graphical representation of some of the common configuration settings that can affect user data rate, and typically do not change: o Pilots On or Off...

  • Page 131: Chapter 7. Adaptive Coding And Modulation (Acm) Option

    FEC Code Rate in response to changing link conditions. ACM may be used in packet-based satellite links (as when using the CDM-750 with Ethernet Interface) to boost system throughput. The basic goal of ACM is to capture historically unused satellite system link margin and convert this margin into additional data throughput.

  • Page 132: Background

    MN-CDM750 Background The CDM-750 system is based on DVB-S2 standards. The DVB standardized a suite of 28 ModCods that work over an Es/No range of -2.3 dB to 16.0 dB (ideal). They have also defined much of the system for both ACM and a related feature called Variable Coding and Modulation (VCM) .

  • Page 133: Example Of Acm Operational Link

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Adaptive Coding and Modulation (ACM) Option MN-CDM750 The Data Rate (DR) and Symbol Rate are related by the symbol rate as follows: DR (Data Rate) = SR (Symbol Rate) x SE (Spectral Efficiency) For a 20 Msps link, this corresponds to the data rates listed in Table 7-1.

  • Page 134: Figure 7-1. Downlink Margin Vs. Average Link Availability

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Adaptive Coding and Modulation (ACM) Option MN-CDM750 for all but 17.5 hours of the year. Figure 7-1 plots the amount of downlink fade margin versus availability for this link. 25 dB 20 dB 15 dB 10 dB 2.5 dB...

  • Page 135: Acm System Description

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Adaptive Coding and Modulation (ACM) Option MN-CDM750 operation provides a higher than contracted level of throughput. Later, a 2.2 dB fade occurs and the ModCod is adjusted to preserve data integrity, causing an adjustment of the data rate to 51 Mbps, which is substantially above the SLA of 25 Mbps.

  • Page 136: Figure 7-3. Acm-Over-Satellite – Generic Example

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Adaptive Coding and Modulation (ACM) Option MN-CDM750 Figure 7-3. ACM-over-Satellite – Generic Example 7–6...

  • Page 137: Acm Scheme

    Revision 1 Adaptive Coding and Modulation (ACM) Option MN-CDM750 CDM-750 ACM Scheme The description of ACM operation in this section serves as the prelude to configuring the CDM-750 for ACM operation. The key items discussed are: • Target Es/No Margin;...

  • Page 138: Distortion Adaptation / Modulation Type Impairment

    The additional impairment allows programming of an offset for each DVB-S2 constellation type, which will ideally match the estimated satellite link distortion. These impairments apply to the forward (transmit) link. The factors are added to CDM-750 specified Es/No for a given constellation. Table 7-4 describes the impairment entry: Table 7-4.

  • Page 139: Pilots

    In addition, 9/10 ModCod is not allowed for short frames, and it is not selectable in short frame mode. The the CDM-750 can be configured for either Normal or short frames, and does not support mixing frame types. When operating in ACM mode, ALWAYS use Normal frames at both ends of the link.

  • Page 140: Monotonic Operation

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Adaptive Coding and Modulation (ACM) Option MN-CDM750 7.4.5 Monotonic Operation Table 7-5 shows the ideal Es/No at QEF for each DVB-S2 ModCod along with spectral efficiency and ModCod #. The QEF or Quasi Error Free point corresponds to a Packet Error Rate (PER) = 10 , based on 188 byte packets.

  • Page 141: Modcod Selection

    The minimum distance between adjacent ModCods must be at least the amount of hysteresis – the figure used for hysteresis is fixed in the CDM-750 at 0.5 dB. The actual Es/No values used are based on the guaranteed Es/No values + Target Es/No Margin + modulation type impairment, not the DVB-S2 ideal Es/No figures.

  • Page 142: Figure 7-6. Spectral Efficiency Vs. Modem Es/No @ Qef (Pruned Modcods)

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Adaptive Coding and Modulation (ACM) Option MN-CDM750 Figure 7-6 presents a practical set of ModCods based on ModCod selection. The pruned or inactive ModCods are shown along the baseline of the plot. The transition to the next higher ModCod is the Es/No (spec) + Es/No Target Margin (user selected) + hysteresis (0.5 dB) +...

  • Page 143: Configuring Acm In The Cdm-750

    Configuring ACM in the CDM-750 ACM operation is a FAST option that must be ordered, then activated in the CDM-750 High Speed Trunking Modem. If this option is not enabled in the modem, contact your Comtech EF Data Sales Representative to upgrade the IMPORTANT modem to support the desired level of ACM operation.

  • Page 144: Table 7-6. Data Rate By Option Symbol Rate

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Adaptive Coding and Modulation (ACM) Option MN-CDM750 Table 7-6. Data Rate by Option Symbol Rate Spectral Maximum Maximum Efficiency Maximum Maximum Maximum ModCod Data Rate Data Rate ModCod 64,800 Data Rate Data Rate...

  • Page 145: Acm Configuration Via The Front Panel

    7.5.1 ACM Configuration via the Front Panel Configuration is very straightforward from the CDM-750 front panel. For a detailed overview of modem operations via the front panel, refer to Chapter 5. FRONT PANEL OPERATION. To configure the CDM-750 for ACM operation, proceed as follows:...

  • Page 146: Acm Congestion Control

    Pause Frame compatibility Figure 7-7. CDM-750 – ACM Congestion Control As shown in Figure 7-7, in order to mitigate packet loss when bandwidth is reduced, the CDM-750 incorporates a WAN buffer. When this WAN buffer cannot accommodate the amount of Ethernet...

  • Page 147: Notes And Recommendations

    Es/No Margin if the fading events are particularly severe and/or frequent. • The value of Max ModCod may be limited by other FAST codes installed in the CDM-750. Example: Suppose the 15 Msps FAST option is installed, and the symbol rate is set to 15 Msps;...

  • Page 148: Acm - Summary Of Specifications

    Eb/No = Es/No – 10log(Spectral Efficiency). • To achieve minimum latency, set the WAN buffer to the smallest practical value. The default setting is 20ms, and Comtech EF Data recommends keeping it at this level. • ACM is 100% compatible with DoubleTalk Carrier-in-Carrier (CnC).

  • Page 149: Chapter 8.  Doubletalk Carrier-In-Carrier Option

    Adaptive Cancellation. Applied Signal uses the term DoubleTalk™, and Comtech EF Data refers to it as DoubleTalk Carrier-in-Carrier (CnC). CnC was first introduced in Comtech EF Data products in the CDM-Qx Satellite Modem and, more recently, in the CLO-10 Link Optimizer and CDM-625 Advanced Satellite Modem.

  • Page 150: Application Requirements

    • Link must be full duplex. • A CDM-750 must be used at the end of the link where the cancellation needs to take place. Normally, this is both ends of the link. • The transponder is operated as Loopback. That is, each end of the link must be able to see a copy of its own signal in the downlink path from the satellite.

  • Page 151: Figure 8-1. Conceptual Block Diagram

    CDM-750 High Speed Trunking Modem Revision 1 DoubleTalk Carrier-in-Carrier Option MN-CDM750 be the differences resulting from antenna size/gain variations between the two ends of the link. An example of the latter would be transient power differences due to different levels of atmospheric fading in the uplinks.

  • Page 152: Operational Details

    245 ms, narrow the search range to 235-255 ms. Factory default for search delay is 230-290 ms. Search delay programmable range is 0-400 ms, where 0 ms is used when doing loop-back or bench testing. • Use the CDM-750’s Internal BERT Tester when evaluating CnC performance. 8–4...

  • Page 153: System Functionality And Operational Considerations

    The transponder downlinks the composite signal containing both carriers on the same band to the CDM-750 which then translates the signal to near baseband where it can be filtered (decimated) and then processed as a complex envelope signal. The CDM-750 then suppresses the version of the near end carrier on the downlink side and then passes the desired carrier to the demodulator for normal processing.

  • Page 154: Figure 8-3. Same Link Using Cdm-750 And Doubletalk Carrier-In-Carrier

    The only caveat to this is that the waveform must be sufficiently random. CDM-750 CnC operates from 1 to 63 Msps. Interference will compromise CnC links just as they do non-CnC links. Acquisition of the demodulator is improved by minimizing the delay search range;...

  • Page 155: Table 8-1. Spectral Efficiency Using Doubletalk Carrier-In-Carrier

    CDM-750 High Speed Trunking Modem Revision 1 DoubleTalk Carrier-in-Carrier Option MN-CDM750 for example, if the delay is known to be around 240ms, set the minimum search delay to 230ms and the maximum search delay to 250ms. As advances in modem technologies – including advanced modulation and FEC techniques –...

  • Page 156: Doubletalk Carrier-In-Carrier Cancellation Process

    CDM-750 High Speed Trunking Modem Revision 1 DoubleTalk Carrier-in-Carrier Option MN-CDM750 8.4.1 DoubleTalk Carrier-in-Carrier Cancellation Process The state-of-the-art signal processing technology employed via CnC continually estimates and tracks all parametric differences between the local uplink signal and its image within the downlink.

  • Page 157: Margin Requirements

    Es/No and maintain the QEF performance. Margin requirements depend on the product, modulation and power ratios; for the CDM-750, these additional margin requirements are as follows:...

  • Page 158: Carrier-In-Carrier Link Design

    CDM-750 High Speed Trunking Modem Revision 1 DoubleTalk Carrier-in-Carrier Option MN-CDM750 8.4.5 Carrier-in-Carrier Link Design CnC link design involves finding the FEC and modulation combination that provides optimal bandwidth utilization. Just like conventional link design, it is an iterative process that involves trying different FEC and modulation combinations with CnC until an optimal combination is found.
  • Page 159 CDM-750 High Speed Trunking Modem Revision 1 DoubleTalk Carrier-in-Carrier Option MN-CDM750 Link parameters and LST summary for 16APSK 2/3 with Carrier-in-Carrier is as follows: 8–11...

  • Page 160: Asymmetric Data Rate Link

    CDM-750 High Speed Trunking Modem Revision 1 DoubleTalk Carrier-in-Carrier Option MN-CDM750 The link budget summary for the different ModCod combinations is as follows: Allocated BW Leased BW Savings Compared PSD Ratio S. No. Modulation & FEC PEB (MHz) (MHz) (MHz)

  • Page 161: Power Limited Links

    CDM-750 High Speed Trunking Modem Revision 1 DoubleTalk Carrier-in-Carrier Option MN-CDM750 If the CnC link was designed using S2-8PSK 3/4 in both directions, it would have required: • Occupied BW – 19.3 MHz; • Power Eq. BW – 17.9 MHz (a 5.9% increase in Power Eq. BW);...

  • Page 162: Carrier-In-Carrier Commissioning And Deployment

    CDM-750 High Speed Trunking Modem Revision 1 DoubleTalk Carrier-in-Carrier Option MN-CDM750 8.4.7 Carrier-in-Carrier Commissioning and Deployment Prior to commissioning a Carrier-in-Carrier link, it is critical that the link is fully tested in non-CnC mode and all system issues – including external interference, antenna pointing, cabling, and SSPA backoff –...

  • Page 163: Operational References

    Procedure Calculate the link budget for both carriers in the duplex link, with required CnC margin: Verify that the CnC ratio is within spec for the CDM-750. Calculate the Allocated Bandwidth (BW) and Power Equivalent Bandwidth (PEB) for the duplex link: •...

  • Page 164: Estimating / Calculating Cnc Ratio

    CDM-750 High Speed Trunking Modem Revision 1 DoubleTalk Carrier-in-Carrier Option MN-CDM750 8.5.2 Estimating / Calculating CnC Ratio CnC Ratio can be derived either from the downlink carrier levels or from the Carrier to Noise Ratio (C/N). 8.5.2.1 Estimating CnC Ratio from LST / EIRP The CnC Ratio is the difference in power of the interferer carrier to the desired carrier.

  • Page 165: Calculating Cnc Ratio From Carrier To Noise Ratio (C/N) On A Spectrum Analyzer

    CDM-750 High Speed Trunking Modem Revision 1 DoubleTalk Carrier-in-Carrier Option MN-CDM750 8.5.2.2 Calculating CnC Ratio from Carrier to Noise Ratio (C/N) on a Spectrum Analyzer For this example, assume Site A is running a link to Site B (referred to as Link 1), and Site...

  • Page 166: Calculating Cnc Ratio And Psd Ratio From Satmaster

    For the complete table of specifications, refer to Sect. 1.4.8 DoubleTalk Carrier-in-Carrier (CnC) in Chapter 1. INTRODUCTION. Carrier-in-Carrier Summary Comtech EF Data’s DoubleTalk Carrier-in-Carrier can provide significant savings in operational expenses. The following considerations must be taken into account when evaluating CnC: •...

  • Page 167: Glossary

    CDM-750 High Speed Trunking Modem Revision 1 DoubleTalk Carrier-in-Carrier Option MN-CDM750 Glossary Bandwidth, Allocated or Occupied Bandwidth or Allocated Bandwidth or Occupied Bandwidth is the frequency space required by a carrier on a transponder. For example, a Duplex 10 Mbps Circuit with 8PSK Modulation, FEC Rate 3/4 and 1.4 Spacing...
  • Page 168 CDM-750 High Speed Trunking Modem Revision 1 DoubleTalk Carrier-in-Carrier Option MN-CDM750 Es/No Ratio of Energy per symbol (Es) to Noise density (No) (unit in dB): Es/No = C/No – 10log(SR) (where SR is the Symbol Rate) Es/No = Eb/No + 10log(SE) (where SE is Spectral Efficiency)
  • Page 169 CDM-750 High Speed Trunking Modem Revision 1 DoubleTalk Carrier-in-Carrier Option MN-CDM750 Quasi Error Free (QEF) Quasi Error Free (QEF) corresponds to PER ~10 PER (packet error rate) is based upon a 188 byte MPEG frame size. Spectral Efficiency (SE) Ratio of the Data Rate to the Symbol Rate.
  • Page 170 CDM-750 High Speed Trunking Modem Revision 1 DoubleTalk Carrier-in-Carrier Option MN-CDM750 Notes: 8–22...

  • Page 171: Chapter 9. Ethernet Network Configuration

    Users to avoid Ethernet looping connection problems – with or without use of the CDM-750 in redundancy. These issues are specifically addressed with a CDM-750 redundancy configuration that uses either a Comtech EF Data CRS-170A (L-Band) or CRS-180 (70/140 MHz) 1:1 Redundancy Switch.

  • Page 172: Ethernet Configuration Examples

    CDM-750 Ethernet Overview 9.4.1 Ethernet Interfaces Figure 9-2 shows the internal Ethernet architecture for the CDM-750. The CDM-750 modem has two built-in 10/100/1000 BaseT Ethernet Ports and an optical Gigabit Ethernet port (for use with the optional SFP module – see Chapter 3. REAR PANEL CONNECTIONS) connected to a single internal Ethernet Layer 2 Switch.

  • Page 173: Ethernet Overhead

    It should also be noted that additional care must be taken to avoid Ethernet Networking Loops as defined in Sect. 9.3.1. Specifically, the network operator must make sure to avoid connecting multiple ports of the CDM-750 to the same external Ethernet switch, as shown in Figure 9-3. 9.4.2 Ethernet Overhead After Ethernet packets are sent from the internal switch to the modem WAN interface, Generic Stream Encapsulation (GSE) is used and overhead is <1%.
  • Page 174 CDM-750 Advanced High-Speed Trunking Modem Revision 1 Ethernet Network Configuration MN-CDM750 Notes: 9–4...

  • Page 175: Chapter 10. Forward Error Correction

    Chapter 10. FORWARD ERROR CORRECTION 10.1 Introduction The CDM-750 Advanced High-Speed Trunking Modem operates with error correction based upon the DVB standards: • DVB-S2 – QPSK, 8PSK, 16APSK and 32APSK with concatenated Low Density Parity Code (LDPC) and Bose-Chaudhuri-Hocquenghem (BCH).

  • Page 176: Range Of Data Rates

    Rate for 35%, and 1.15 x Symbol Rate for 25%. Figure 10-1 through Figure 10-4 illustrate the guaranteed error performance characteristics of the CDM-750 while running with Normal frames (64,800 bits), Pilots ON. QPSK 1/4, 1/3, 2/5 are shown for information only and are not available in the CDM-750.

  • Page 177: Figure 10-1. Dvb-S2 Qpsk Packet Error Rate Versus Es/No

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Forward Error Correction MN-CDM750 1.0E-02 DVB‐S2: QPSK PER vs Es/No 1.0E-03 9/10 1.0E-04 1.0E-05 1.0E-06 1.0E-07 Es/No (dB) Figure 10-1. DVB-S2 QPSK Packet Error Rate versus Es/No (QPSK 1/4, 1/3, and 2/5 provided for information only) 10–3...

  • Page 178: Figure 10-2. Dvb-S2 8Psk Packet Error Rate Versus Es/No

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Forward Error Correction MN-CDM750 1.0E-02 DVB‐S2: 8‐PSK PER vs Es/No 1.0E-03 9/10 1.0E-04 1.0E-05 1.0E-06 1.0E-07 Es/No (dB) Figure 10-2. DVB-S2 8PSK Packet Error Rate versus Es/No 10–4...

  • Page 179: Figure 10-3. Dvb-S2 16Apsk Packet Error Rate Versus Es/No

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Forward Error Correction MN-CDM750 1.0E-02 DVB‐S2: 16‐APSK PER vs Es/No 1.0E-03 9/10 1.0E-04 1.0E-05 1.0E-06 1.0E-07 Es/No (dB) Figure 10-3. DVB-S2 16APSK Packet Error Rate versus Es/No 10–5...

  • Page 180: Figure 10-4. Dvb-S2 32Apsk Packet Error Rate Versus Es/No

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Forward Error Correction MN-CDM750 1.0E-02 DVB‐S2: 32‐APSK PER vs Es/No 1.0E-03 9/10 1.0E-04 1.0E-05 1.0E-06 1.0E-07 Es/No (dB) Figure 10-4. DVB-S2 32APSK Packet Error Rate versus Es/No 10–6...

  • Page 181: Introduction

    The G.703 E3/T3/STS-1 Plug-In Interface Card (PIIC) (Figure 11-1) is a module that plugs into either or both of the Interface Option slots located on the rear panel of the CDM-750 Advanced High-Speed Satellite Modem chassis. It provides physical and electrical connection between the external terrestrial device and the internal circuitry of the modulator or demodulator.

  • Page 182: Physical Description

    CDM-750 Advanced High Speed Trunking Modem Revision 1 G.703 E3/T3/STS-1 Plug-In Interface Card (PIIC) MN-CDM750 11.2 Physical Description Figure 11-2 depicts the block diagram of the interface: Figure 11-2. G.703 E3/T3/STS-1 PIIC Block Diagram Figure 11-3 shows the rear panel of the interface: the physical interfaces provided are as follows (left to right): •...

  • Page 183: E3/T3/Sts-1 Piic Connectors And Pinouts

    CDM-750 Advanced High Speed Trunking Modem Revision 1 G.703 E3/T3/STS-1 Plug-In Interface Card (PIIC) MN-CDM750 11.3 G.703 E3/T3/STS-1 PIIC Connectors and Pinouts Connector Description Direction Connector Type TX-IN Data In RX-OUT Data Out BNC Female CLK-IN Ext Clock Input 11.4 Installing the G.703 E3/T3/STS-1 PIIC Two slots that accommodate the G.703...

  • Page 184: Summary Of Specifications

    CDM-750 Advanced High Speed Trunking Modem Revision 1 G.703 E3/T3/STS-1 Plug-In Interface Card (PIIC) MN-CDM750 11.5 Summary of Specifications 11.5.1 General Specifications Item Description Interfaces 1 - Tx G.703 port, E3, T3, STS-1 Input 1 - Rx G.703 port, E3, T3, STS-1 Output 1 –...

  • Page 185: Appendix A. Es/No Measurement

    Appendix A. Es/No MEASUREMENT Although the CDM-750 Advanced High-Speed Trunking Modem calculates and displays the value of receive Es/No on the front panel of the unit, it is sometimes useful to measure the value using a spectrum analyzer, if one is available.
  • Page 186 CDM-750 Advanced High-Speed Trunking Modem Revision 1 Appendix A MN-CDM750 Example: In the diagram that follows, the (Co+No)/No measured is 4.6 dB. If Rate 1/2 QPSK is used, this corresponds to an Es/No of approximately 2.8 dB (DVB-S2). The relationship used to derive the table values (the only simple way for DVB-S2) is as follows:...

  • Page 187: Table A-1. Cdm-750 Co+No/No To C/N (Es/No) And Eb/No (Db) For Dvb-S2 Qpsk And 8Psk

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Appendix A MN-CDM750 Table A-1. CDM-750 Co+No/No to C/N (Es/No) and Eb/No (dB) for DVB-S2 QPSK and 8PSK (DVB-S2 uses C/N (Es/No), and Eb/No is shown for information) QPSK 8PSK Spectral Efficiency Pilots ON ►...

  • Page 188: Table A-2. Cdm-750 Co+No/No To C/N (Es/No) And Eb/No (Db) For Dvb-S2 16Apsk And 32Apsk

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Appendix A MN-CDM750 Table A-2. CDM-750 Co+No/No to C/N (Es/No) and Eb/No (dB) for DVB-S2 16APSK and 32APSK (DVB-S2 uses C/N (Es/No), and Eb/No is shown for information) 16APSK 32APSK Spectral Efficiency Pilots ON ►...

  • Page 189: Appendix B.  Ethernet Statistics And Status Reporting

    Es/No, RSL, etc.) in order to focus strictly on data traffic-related items. Data Flow Diagram A way to visualize the CDM-750 and its data traffic handling capabilities is via the simplified diagram shown on the next page (Figure B-1). While this figure includes a few of the normal modulator and demodulator features, its primary purpose is to emphasize the blocks involved in data flow.

  • Page 190: Figure B-1. Cdm-750 Data Flow Diagram

    The microcontroller (µP) is involved in collection and calculation of statistics. µP / M&C / Management IF Region This unmarked region of the diagram refers to data to or from the satellite link. Figure B-1. CDM-750 Data Flow Diagram B–2...

  • Page 191: Statistics Items

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Appendix B MN-CDM750 Statistics Items The tabulated content as presented in the sections that follow may or may not be operational at this time. B.3.1 Ethernet Data Statistics Fig. B-1 Block Flow Item...

  • Page 192: Status Items

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Appendix B MN-CDM750 Status Items Status items are not strictly part of the Statistics but are important items used for monitoring for current conditions. B.4.1 BER Testing Item Comments ModCod Selection Allows selection of ModCod for test.

  • Page 193: Appendix C. Fast Activation Procedure

    If, at a later date, the user wishes to upgrade the functionality of a modem, Comtech EF Data provides Fully Accessible System Topology (FAST), which facilitates on-location upgrade of the operating feature set without removing a modem from the setup.

  • Page 194: Fast Activation Procedure

    Register 3 is for the K4 GZip lossless compression and decompression option. Note the following: • When a FAST Access Code is obtained from Comtech EF Data, it will be for a specific register. • The CnC and K4 GZip FAST options require installation of the respective option card into the internal modem board.

  • Page 195: Order Fast Options

    Contact a Comtech EF Data sales representative during normal business hours to order features. You will be asked to provide the modem serial number. Comtech EF Data Customer Support personnel will then verify the order and provide an invoice and instructions, including the 20- digit FAST Access Code required for configuration.
  • Page 196 CDM-750 Advanced High-Speed Trunking Modem Revision 1 Appendix C MN-CDM750 Notes: C–4...

  • Page 197: Appendix D. Remote Control

    Appendix D. REMOTE CONTROL Overview This appendix describes the protocol and message command set for remote monitor and control of the CDM-750 Advanced High-Speed Trunking Modem. The electrical interface is an EIA-232 connection (for the control of a single device), and data is transmitted in asynchronous serial form, using ASCII characters.

  • Page 198: Basic Protocol

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Appendix D MN-CDM750 mode, via one of the pairs. Many ‘target’ devices are connected to this pair, which all simultaneously receive data from the controller. The controller is the only device with a line-driver connected to this pair - the target devices only have line-receivers connected.

  • Page 199: Packet Structure

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Appendix D MN-CDM750 Packet Structure Controller-to-Target Optional Start of Packet Target Address Address Delimiter Instruction Code Code Qualifier End of Packet Arguments < = or ? Carriage Return ASCII code 60 ASCII code 47...

  • Page 200: Address Delimiter

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Appendix D MN-CDM750 Important note: The controller sends a packet with the address of a target - the destination of the packet. When the target responds, the address used is the same address, to indicate to the controller the source of the packet. The controller does not have its own address.

  • Page 201: Optional Message Arguments

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Appendix D MN-CDM750 The ? code (target to controller) is only used as follows: (ASCII code 63) If the controller sends an instruction to set a parameter to a particular value, then, if the value sent in the argument is not valid, the target will acknowledge the message by replying, for example, with TFQ? (with no message arguments).

  • Page 202: Remote Commands And Queries

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Appendix D MN-CDM750 Remote Commands and Queries Index Notes: Column ‘C’=Command; Column ‘Q’=Query; columns marked ‘X’ designate instruction code as Command only, Query only, or Command/Query. CODE PAGE CODE PAGE CODE PAGE CODE...

  • Page 203: Tx Parameters

    Sets Tx Frequency range in the form xxxx.xxxx: TFQ* 50 MHz to 180 MHz, and 950 MHz to 2150 MHz TFQ# Tx Frequency Resolution=100Hz. Note: The CDM-750 supports 70/140 MHz band and L-Band. Example: TFQ=0950.9872 Tx Gold Code Command or Query. TGS= TGS=...
  • Page 204 CDM-750 Advanced High-Speed Trunking Modem Revision 1 Appendix D MN-CDM750 Command Query Parameter Number of Response to (Instruction Description of Arguments (Instruction & Response to Query Type Arguments Command & Qualifier) Qualifier) TX LO TLO= 6 bytes Command or Query.
  • Page 205 CDM-750 Advanced High-Speed Trunking Modem Revision 1 Appendix D MN-CDM750 Command Query Parameter Number of Response to (Instruction Description of Arguments (Instruction & Response to Query Type Arguments Command & Qualifier) Qualifier) Command or Query. Tx MODCOD TMC= 2 bytes...
  • Page 206 CDM-750 Advanced High-Speed Trunking Modem Revision 1 Appendix D MN-CDM750 Command Query Parameter Number of Response to (Instruction Description of Arguments (Instruction & Response to Query Type Arguments Command & Qualifier) Qualifier) TSR= 10 bytes, numeric Command or Query. TSR? TSR? TSR=xxxxxx.xxx...

  • Page 207: Rx Parameters

    Rx Frequency ranges in the form xxxxxx.xxx: Arguments) RFQ* Resolution=100Hz RFQ# 50 MHz to 180 MHz, and 950 MHz to 2150 MHz Note: The CDM-750 supports 70/140 MHz bands and L-Band. Example: RFQ=0950.9872 Rx Gold Code Command or Query. RGS= RGS= 6 bytes...
  • Page 208 CDM-750 Advanced High-Speed Trunking Modem Revision 1 Appendix D MN-CDM750 Command Query Parameter Number of Response to (Instruction Description of Arguments (Instruction & Response to Query Type Arguments Command & Qualifier) Qualifier) Query only. Rx MODCOD RMC= RMC? RMC=xx RMC?
  • Page 209 CDM-750 Advanced High-Speed Trunking Modem Revision 1 Appendix D MN-CDM750 Command Query Parameter Number of Response to (Instruction Description of Arguments (Instruction & Response to Query Type Arguments Command & Qualifier) Qualifier) RX LO RLO= 6 bytes Command or Query.

  • Page 210: Ip Packet Parameters

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Appendix D MN-CDM750 D.6.3 IP Packet Parameters Command Query Parameter Number of Response to (Instruction Description of Arguments (Instruction & Response to Query Type Arguments Command & Qualifier) Qualifier) Command only. Clear CCS=...
  • Page 211 CDM-750 Advanced High-Speed Trunking Modem Revision 1 Appendix D MN-CDM750 Command Query Parameter Number of Response to (Instruction Description of Arguments (Instruction & Response to Query Type Arguments Command & Qualifier) Qualifier) Query only. IP Statistics 143 bytes ST1? ST1= XXE+XX: XXE+XX: XXE+XX: XXE+XX: Queries all IP Statistics –...

  • Page 212: Unit Parameters

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Appendix D MN-CDM750 D.6.4 Unit Parameters Command Query Parameter Number of Response to (Instruction Description of Arguments (Instruction & Response to Query Type Arguments Command & Qualifier) Qualifier) Command or Query. Adjustment for...
  • Page 213 CDM-750 Advanced High-Speed Trunking Modem Revision 1 Appendix D MN-CDM750 Command Query Parameter Number of Response to (Instruction Description of Arguments (Instruction & Response to Query Type Arguments Command & Qualifier) Qualifier) Command or Query. External EFR= 1 byte, EFR=...
  • Page 214 CDM-750 Advanced High-Speed Trunking Modem Revision 1 Appendix D MN-CDM750 Command Query Parameter Number of Response to (Instruction Description of Arguments (Instruction & Response to Query Type Arguments Command & Qualifier) Qualifier) LC1= 1 byte, value 1 Command or Query.
  • Page 215 CDM-750 Advanced High-Speed Trunking Modem Revision 1 Appendix D MN-CDM750 Command Query Parameter Number of Response to (Instruction Description of Arguments (Instruction & Response to Query Type Arguments Command & Qualifier) Qualifier) Command or Query. Unit Alarm Mask MSK= 36 bytes...
  • Page 216 CDM-750 Advanced High-Speed Trunking Modem Revision 1 Appendix D MN-CDM750 Command Query Parameter Number of Response to (Instruction Description of Arguments (Instruction & Response to Query Type Arguments Command & Qualifier) Qualifier) Query only. Retrieve next 5 80 bytes RNE?
  • Page 217 CDM-750 Advanced High-Speed Trunking Modem Revision 1 Appendix D MN-CDM750 Command Query Parameter Number of Response to (Instruction Description of Arguments (Instruction & Response to Query Type Arguments Command & Qualifier) Qualifier) SNMP 255 bytes, Command or Query. SSC = SSC =x [1..128]...
  • Page 218 CDM-750 Advanced High-Speed Trunking Modem Revision 1 Appendix D MN-CDM750 Command Query Parameter Number of Response to (Instruction Description of Arguments (Instruction & Response to Query Type Arguments Command & Qualifier) Qualifier) Command or Query. Test Mode TST= 1 byte,...

  • Page 219: Acm Parameters

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Appendix D MN-CDM750 D.6.5 ACM Parameters Command Query Parameter Number of Response to (Instruction Descriptiono of Arguments (Instruction & Response to Query Type Arguments Command & Qualifier) Qualifier) Command or Query. ACM Operating...
  • Page 220 CDM-750 Advanced High-Speed Trunking Modem Revision 1 Appendix D MN-CDM750 D.6.6 G.703 Parameters Command Query Parameter Number of Response to (Instruction Descriptiono of Arguments (Instruction & Response to Query Type Arguments Command & Qualifier) Qualifier) Interface EFI= 2 bytes Command or Query.
  • Page 221 CDM-750 Advanced High-Speed Trunking Modem Revision 1 Appendix D MN-CDM750 Command Query Parameter Number of Response to (Instruction Descriptiono of Arguments (Instruction & Response to Query Type Arguments Command & Qualifier) Qualifier) Rx Buffer Size RBS= 6 bytes Command or Query.

  • Page 222: Bulk Configuration Strings

    Qualifier) Global MGC= 224 bytes, Command or Query. MGC= MGC? MGC=FFFF.FFFFDDDDD. Configuration numerical entries, Global Configuration of CDM-750, in the form shown in the ‘Response to Query’ DDDGYRMVSPP.PBaaa.aa MGC? fixed values and column, where: CXIKNZffff.ffffddddd.dddgyr MGC* delimiters mvswwwcll.lbbbbbiknzOEE FFFF.FFFF=Tx Frequency...
  • Page 223 CDM-750 Advanced High-Speed Trunking Modem Revision 1 Appendix D MN-CDM750 Command Query Parameter Number of Response to (Instruction Descriptiono of Arguments (Instruction & Response to Query Type Arguments Command & Qualifier) Qualifier) 11111111111111111111=PIIC Card 1 Configuration see Notes 1-3 22222222222222222222=PIIC Card 2 Configuration...

  • Page 224: Modem Information

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Appendix D MN-CDM750 D.6.8 Modem Information Command Query Parameter Number of Response to (Instruction Description of Arguments (Instruction & Response to Query Type Arguments Command & Qualifier) Qualifier) Query only. Equipment ID 33 bytes...
  • Page 225 T=Gzip 0=not installed, 1=installed U=Reserved (Transec 0=not installed, 1=installed) V=Optical 0= not installed, 1=installed W=GZIP Tx Symbol Rate 0=NONE 1=5M 2=15M 3=34M 4=47M 5=63M X=Reserved Y-Z=Spares (reserved and indicated with an X) Example: EID= 07500000000000000000000000000XXXX is a CDM-750 with no options installed. D–29...
  • Page 226 CDM-750 Advanced High-Speed Trunking Modem Revision 1 Appendix D MN-CDM750 Command Query Parameter Number of Response to (Instruction Description of Arguments (Instruction & Response to Query Type Arguments Command & Qualifier) Qualifier) Query only. Firmware 100 bytes FRW?1 FRW=XXXXXX information...

  • Page 227: Modem Performance Information

    CDM-750 Advanced High-Speed Trunking Modem Revision 1 Appendix D MN-CDM750 D.6.9 Modem Performance Information Command Query Parameter Number of Response to (Instruction Description of Arguments (Instruction & Response to Query Type Arguments Command & Qualifier) Qualifier) BERT 10E-3 BKE= 1 byte Command only.
  • Page 228 CDM-750 Advanced High-Speed Trunking Modem Revision 1 Appendix D MN-CDM750 Command Query Parameter Number of Response to (Instruction Description of Arguments (Instruction & Response to Query Type Arguments Command & Qualifier) Qualifier) Query only. Rx Eb/No 4 bytes EBN? EBN=...
  • Page 229 CDM-750 Advanced High-Speed Trunking Modem Revision 1 Appendix D MN-CDM750 Command Query Parameter Number of Response to (Instruction Description of Arguments (Instruction & Response to Query Type Arguments Command & Qualifier) Qualifier) 9 bytes FLT? Faults and 5= G.703 PIIC2 Symbol Clock PLL FLT=aabccdexx Status (cont.)
  • Page 230 CDM-750 Advanced High-Speed Trunking Modem Revision 1 Appendix D MN-CDM750 Command Query Parameter Number of Response to (Instruction Description of Arguments (Instruction & Response to Query Type Arguments Command & Qualifier) Qualifier) Query only. Rx Frequency 6 bytes RFO? RFO=sxxx.x...

  • Page 231: Metric Conversions

    METRIC CONVERSIONS Units of Length Unit Centimeter Inch Foot Yard Mile Meter Kilometer Millimeter 1 centimeter — 0.3937 0.03281 0.01094 6.214 x 10 0.01 — — 1 inch 2.540 — 0.08333 0.2778 0.254 — 25.4 1.578 x 10 1 foot 30.480 12.0 —...
  • Page 232 2114 85281 WEST TH STREET TEMPE ARIZONA 480 • 333 • 2200 PHONE 480 • 333 • 2161...

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