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Microcom Design ucom DAMS-NT DigiRIT Operation Manual

Digital lrit/hrit receiver
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DAMS-NT DigiRIT
Digital LRIT/HRIT Receiver
Operation Manual
Release 1 - Revision A
12/14/2012
Microcom Design, Inc.
10948 Beaver Dam Road, Suite C
Hunt Valley, MD 21030

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Summary of Contents for Microcom Design ucom DAMS-NT DigiRIT

  • Page 1 DAMS-NT DigiRIT Digital LRIT/HRIT Receiver Operation Manual Release 1 - Revision A 12/14/2012 Microcom Design, Inc. 10948 Beaver Dam Road, Suite C Hunt Valley, MD 21030...

  • Page 2: Table Of Contents

    Release 1 DAMS-NT DigiRIT Operation Manual 12/14/2012 Table of Contents Table of Contents..........................i List of Figures ..........................ii List of Tables ..........................iii List of Appendices ......................... iii Introduction..........................4 1.1. Manual Organization ......................4 1.2. Background ......................... 4 1.3.

  • Page 3: List Of Figures

    Release 1 DAMS-NT DigiRIT Operation Manual 12/14/2012 3.1.2. Programming the IF Frequency ..................24 3.1.3. Setting the IF Attenuation....................25 3.1.4. Enabling/Disabling the LNA (Front-End) DC Power ........... 25 3.1.5. Configuring the LRIT DCS Virtual Channels ............... 26 3.1.6. Completing the Pushbutton Setup Process ..............27 3.2.
  • Page 4 Release 1 DAMS-NT DigiRIT Operation Manual 12/14/2012 List of Tables Table 1: 55-Character DCP Message Header Format..............10 Table 2: Error/Message Flag Values.................... 11 Table 3: DRGS Source Code to Slot Number ................33 List of Appendices APPENDIX A: Acronyms and Abbreviations................37...

  • Page 5: Introduction

    Release 1 DAMS-NT DigiRIT Operation Manual 12/14/2012 Introduction The Microcom Design, Inc. DAMS-NT DigiRIT system is an easy-to-use, low-cost solution to receive satellite information from National Oceanographic Atmospheric Administration’s (NOAA) Geostationary Operational Environmental Satellite (GOES) Data Collection System (DCS) via the Low Rate Information Transmission (LRIT) re-broadcast. The...

  • Page 6: Figure 1: Major Elements Of Goes Dcs

    Telecommunications Gateway (NWSTG), NOAA’s Low Rate Information Transmission (LRIT) satellite link, a user developed Local Readout Ground System (LRGS) network, and the DADDS Internet website. The NESDIS GOES DCS resource’s are allocated and administered by NESDIS from the NSOF facility. Microcom Design, Inc.

  • Page 7: Theory Of Operation

    Only one of these inputs can be specified as the active input. Both inputs are capable of sourcing a DC supply for the front-end. In most cases, the IF signal delivered by the front-end includes both the raw DCS spectrum and the LRIT transmission, as well as numerous other GOES RF Microcom Design, Inc.
  • Page 8 On the other hand, while it is not necessary to get the LRIT stream from both spacecrafts, there is one distinct advantage to utilizing two DigiRIT systems, one for GOES-East and one for GOES- West; specifically, redundancy. Adding a second DigiRIT antenna and receiver to get the LRIT Microcom Design, Inc.

  • Page 9: Digirit Receiver Overview

    Figure 4: DigiRIT Receiver Rear Panel Referring to the above figures, provided below is a list of the DigiRIT’s connection points, controls, and indicators. Status Display N/A RS-232 Test Port SUB-D-9F LED Status Indicators DigiRIT Setup Pushbuttons Microcom Design, Inc.

  • Page 10: Dams-Nt Dcp Message Interface

    However, minor deviations from the specification imposed by limitations in the raw LRIT message format are discussed below. All fields, including the StartPattern, in the header are in ASCII without any parity. Microcom Design, Inc.

  • Page 11: Table 1: 55-Character Dcp Message Header Format

    The Spacecraft field designates the GOES satellite the message was received on, East or West. Note this is the spacecraft the original DCS message was transmitted through, not the LRIT spacecraft. As with the Channel field, the information is provided via the LRIT data and is simply copied. Microcom Design, Inc.

  • Page 12: Table 2: Error/Message Flag Values

    Loss of lock termination (i.e., no EOT) 0x10 Message contains Carrier Times The OrigAddress and DcpAddress will contain the same information; specifically, the GOES DCS Platform ID or Address that transmitted the message. The GOES DCP ID is an eight Microcom Design, Inc.

  • Page 13: Dams-Nt Message Data

    If the Carrier Times are included, they will immediately follow the CR/LF that terminates the message data portion. The format the for the Carrier Times section is CarrierStart followed by a single space followed by CarrierDrop followed by a CR/LF. Further, whenever the Carrier Microcom Design, Inc.

  • Page 14: Lrit Tcp/Ip Interface

    1020 bytes of “scrambled” data. The DigiRIT applies the LRIT defined descrambler to the data to produce what is called the Virtual Channel Data Unit or VCDU. Each VCDU consists of a 6-byte header, an 886-byte data zone, and 128 bytes of Reed Solomon encoded check symbols. Microcom Design, Inc.

  • Page 15: Antenna Front End Power

    100-240 VAC at either 50 or 60 Hz. While the AC Power Input and On/Off switch (see Section 2.2.2.5) also includes an integral 1 Amp Fuse, the maximum power required is less than 30 Watts. Microcom Design, Inc.

  • Page 16: Dams-Nt Digirit Hardware Setup

    DigiRIT Receiver will be factory configured to be plug-and-play. For most installations, only two cable connections will be required at the receiver besides AC Power. Specifically, an Antenna IF Input connection and the DCS TCP/IP connection. Microcom Design, Inc.

  • Page 17: Front Panel Connections, Controls And Indication

    Configuration information is automatically saved to non-volatile memory and recalled whenever the Receiver is powered up, i.e. the unit should always come up in the same operational state as it was in prior to shutdown or power loss. MICROCOM DESIGN INC MICROCOM DESIGN INC MICROCOM DESIGN INC...

  • Page 18: Figure 7: Digirit Status Screen

    • VS => has achieved Viterbi sync • FS => has acquired LRIT frame sync Once the receiver DigiRIT Receiver had acquired frame sync, it is capable of receiving DCS messages and the SIGNAL ACQUIRED LED will turn from red to green. Microcom Design, Inc.

  • Page 19: Front Panel Leds

    This test connector is primarily provided to allow an easy connection point for monitoring the 70 MHz IF on a Spectrum Analyzer. Note that even when DC power is provided to the 70 MHz Antenna Input, the DC is NOT present on the 70 MHz Test connector. Microcom Design, Inc.

  • Page 20: 140 Mhz Test Connector

    2.2.2.1.2. Antenna IF Out The Antenna IF Output provides a buffered output of the 70/140 MHz IF input similar to that provided on the Front Panel (see Sections 2.2.1.5 and 2.2.1.6). The primary purpose of this Microcom Design, Inc.

  • Page 21: Dcs Tcp/Ip Network Connection

    For installations that require a safety ground, a case ground lug is also provided on the Rear Panel. Connection of this lug to Earth ground is not required for operation, but is simply provided when it is not sufficient or adequate to count on the case being grounded via the mounting structure. Microcom Design, Inc.

  • Page 22: Cooling Fan

    Release 1 DAMS-NT DigiRIT Operation Manual 12/14/2012 2.2.2.8. Cooling Fan Located on the Rear Panel is small cooling fan. Do not obstruct the air flow around the cooling fan. Microcom Design, Inc.

  • Page 23: Digirit Receiver Configuration

    Receiver; via the Front Panel SETUP/SELECT pushbuttons and via the Front Panel Test Port. These are covered in Sections 3.1 and 3.2, respectively. In addition to the basic operational setup, the network IP parameters can also be adjusted as explained in Section 3.3. Microcom Design, Inc.

  • Page 24: Front Panel Pushbutton Setup

    • LNA Power On/Off – Section 3.1.4 This allows the unit to be fully pre-configured for both inputs, and quickly switch from one to the other. This can be useful if the DigiRIT is connected to both a dedicated primary LRIT feed Microcom Design, Inc.

  • Page 25: Programming The If Frequency

    To facilitate entering the IF Frequency the following special conditions are employed by the DigiRIT when selecting the desired frequency: • The first digit for the 140 MHz IF Frequency is not editable and will always be ‘1’, i.e. the cursor will never be placed on this digit. Microcom Design, Inc.

  • Page 26: Setting The If Attenuation

    SET 140 140MHz LNA POWER MHz LNA POWER SET 140 140MHz LNA POWER MHz LNA POWER MHz LNA POWER MHz LNA POWER MHz LNA POWER MHz LNA POWER Figure 12: Turning the LNA Power ON and OFF Microcom Design, Inc.

  • Page 27: Configuring The Lrit Dcs Virtual Channels

    The following rules apply to the VC Buffer Allocation settings: • The corresponding buffer allocation for a VC set to 63 must be 0 (zero). • A VC value of in the range of 00-62, must have a non-zero allocation value. Microcom Design, Inc.

  • Page 28: Completing The Pushbutton Setup Process

    19.2k BPS with 8 data bits, no parity, 1 stop bit and no flow control. The Test Port interface is always in one of two states. First, a continuous monitor loop provides current operational status in a serious of text lines output once a second. Second, a text based Microcom Design, Inc.

  • Page 29: Test Port Status Report

    Generally speaking, pressing the ESC key at any menu will exit the current menu and return to the parent. For example; pressing ESC with the System Information displayed, will return to the Main Menu. Microcom Design, Inc.

  • Page 30: System Setup Menu

    As indicated, pressing ESC will abandon any changes made since the last save operation and exit the System Setup menu. If no changes have been made since the last “Save & Apply” operation, the DigiRIT will simply exit this menu and return to the Main Menu. Microcom Design, Inc.

  • Page 31: Virtual Channel Setup Menu

    Section 3.1.5 are applied. As was the case with the System Setup menu, the ‘S’ menu option saves and applies any changes. Likewise, ESC exits the menu, abandoning any changes made since the last save operation. Microcom Design, Inc.

  • Page 32: Message Setup Menu

    The default setting is disabled or “DIS”, in which case the DigiRIT will report ‘0300’ in the DAMS-NT header when the Baud rate is unknown. To change this setting, the user must access the Message Setup menu and at the selection prompt type “B=xxx”, where “xxx” is Microcom Design, Inc.

  • Page 33: Slot Number Mode Option

    Table 3. These mappings cover the three major receive sites and also several medium size DRGS systems. As Table 3 indicates, if the DRGS sourcing the message is not known or cannot be identified in the LRIT stream, then the Slot Number will be reported as ‘999’. Microcom Design, Inc.

  • Page 34: Network Interface Configuration

    This screen provides several useful pieces of information including the Model and Serial Number of the module, the current Firmware version (of the Moxa module, not the DigiRIT) and the unique MAC Address of the Moxa module. Microcom Design, Inc.

  • Page 35: Figure 21: Miineport Web Console - Overview Screen

    For example, to change the Port for the interface, select the “Operation Modes” option and the settings within this group will be displayed as shown in Figure 24. Microcom Design, Inc.

  • Page 36: Figure 23: Web Console - Save/Restart

    Figure 24: Web Console – Operation Modes Settings As is readily apparent from the screen shots shown so far, the Moxa MiiNePort E2 module has numerous optional settings. While some of these cannot be altered, as noted above, others can Microcom Design, Inc.

  • Page 37: Figure 25: Web Console - Settings Saved

    Web Console. Naturally, any Clients that had previously connected to the changed DigiRIT socket must also be updated accordingly. Figure 25: Web Console – Settings Saved Microcom Design, Inc.

  • Page 38: Appendix A: Acronyms And Abbreviations

    Direct Readout Ground Station Digital Signal Processor; Digital Signal Processing EIRP Equivalent Isotropic Radiated Power EOT, ETX End of Transmission Frame Synch Sequence GOES Geostationary Operational Environmental Satellite Graphical User Interface HRIT High Rate Information Transmission Hertz Microcom Design, Inc.
  • Page 39 NWSTG National Weather Service Telecommunications Gateway O&M Operations and Maintenance Original Equipment Manufacturer Operating System Phase Modulation ppm, PPM parts per million Phase Shift Keying Quad Mother Board (DAMS-NT) Radio Frequency Symbols per Second sync Synchronizer; Synchronization Microcom Design, Inc.
  • Page 40 DAMS-NT DigiRIT Operation Manual 12/14/2012 Transfer Control Protocol U.S. United States Ultra High Frequency (401.7 to 402.1 MHz for this DCS application) Volts Virtual Channel Volts peak-to-peak WCDA Wallops Command and Data Acquisition WCDAS Wallops Command and Data Acquisition Station Microcom Design, Inc.

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