1. Manuals
  2. Brands
  3. General DataComm Manuals
  4. Network Hardware
  5. 551
  6. Operating and installation instructions

General DataComm 551 Operating And Installation Instructions

Intelligent channel service unit
Hide thumbs
Table of Contents

Advertisement

Quick Links

Download this manual
Publication No. 048R138-000
Issue 8, September 2005
OPERATING AND INSTALLATION INSTRUCTIONS
FOR
DataComm 551 INTELLIGENT
CHANNEL SERVICE UNIT
General DataComm, Inc.
NAUGATUCK, CONNECTICUT
06770 U.S.A.

Advertisement

Table of Contents
loading

Related Manuals for General DataComm 551

Summary of Contents for General DataComm 551

  • Page 1 Publication No. 048R138-000 Issue 8, September 2005 OPERATING AND INSTALLATION INSTRUCTIONS DataComm 551 INTELLIGENT CHANNEL SERVICE UNIT General DataComm, Inc. NAUGATUCK, CONNECTICUT 06770 U.S.A.
  • Page 2 ATTENTION! STATIC SENSITIVE DEVICES PROPER HANDLING AND GROUNDING PRECAUTIONS REQUIRED This equipment contains electrostatic sensitive devices. Use ESD pre- cautionary procedures when removing or inserting parts or printed circuit (pc) cards. Keep parts and pc cards in their antistatic packaging material until ready to install.
  • Page 3 (GDC PART NOS. 048A018-001 and 048P037-001) APPLICABILITY This manual applies only to assembly-level Revision (P) and LATER DataComm 551 pc cards. (The information regarding the Transcoding and Unframed Mode options applies only to assembly-level Revision (Y) and LATER DataComm 551 pc cards.) Use Publication No.
  • Page 4 P.O Box 1299 Middlebury, CT 06762-1299 PROPRIETARY NOTICE This publication contains information proprietary and confidential to General DataComm, Inc. Any reproduction, disclosure, or use of this publication is expressly prohibited except as General DataComm, Inc., may otherwise authorize in writing.
  • Page 5 Regulations. Connection of data communication equipment to the public telephone network is regulated by the FCC Rules and Regulations. These regulations require: To connect the DC 551 to the Public Telephone Network you are required to give the Telephone Company the following information.
  • Page 6 CANADIAN DEPARTMENT OF COMMUNICATIONS (DOC) REQUIRED NOTIFICATION FOR USERS OF DOC-CERTIFIED EQUIPMENT Read before using this technical manual or installing subject equipment. The Canadian Department of Communications label identifies certified equipment. This certification means that the equipment meets certain telecommunications network protective, operational, and safety requirements.
  • Page 7 AFFIDAVIT FOR THE CONNECTION OF CUSTOMER PREMISES EQUIPMENT TO 1.544 Mbps AND/OR SUBRATE DIGITAL SERVICES For work to be performed in the certified territory of (Telco’s Name) State of: County of: I, , (Name) Business Address representing (Name of Customer) being duly sworn, state: (Telephone Number) I have the responsibility for the operation and maintenance of the terminal equipment to be...
  • Page 8 I attest that the operator(s)/maintainer(s) of the digital CPE responsible for the establish- ment, maintenance and adjustment of the encoded analog content and billing information has (have) been trained to perform these functions by successfully completing one of the following: (Check appropriate one(s) ). A training course provided by the manufacturer/grantee of the equipment used to encode analog signals A training course provided by the customer or authorized representative,...
  • Page 9 City __________________________ State ____________ Zip Code or Country _____________ Telephone Number if you want us to call you ( ____ ) _____ - _________ Copy or remove this page and mail to: Publications Department Technology Center General DataComm Industries, Inc. Middlebury, Ct 06762-1299...

  • Page 11: Table Of Contents

    TABLE OF CONTENTS Section & Subject Page 1 — INTRODUCTION DataComm 551 FEATURES.........................1-1 DESCRIPTION ............................1-1 DIAGNOSTICS ............................1-2 APPLICATIONS............................1-3 BACKWARD COMPATIBILITY.........................1-6 SERVICE AND TRAINING ........................1-6 2 — INSTALLATION OVERVIEW ..............................2-1 UNPACKING AND HANDLING........................ 2-1 PREOPERATIONAL CHECK ........................2-1 INSTALLATION PROCEDURES........................ 2-1 OPTION SELECTION ..........................2-5...
  • Page 12 TABLE OF CONTENTS (Cont.) Section & Subject Page 4 — TESTS OVERVIEW ..............................4-1 DS1 LOOPBACK FUNCTIONS ........................4-4 DS1 Line Loopback Function........................4-4 DS1 Network Interface Loopback Function....................4-5 DS1 Test Loopback Function ........................4-6 DS1 DIAGNOSTICS.............................4-7 DS1 Line Loop ............................4-7 DS1 Local Test ............................4-8 DS1 Local Test with Self-Test........................4-9 DS1 Network Interface Loopback ......................4-10 DS1 Network Interface Loopback with Self-Test ..................4-11...
  • Page 13 TABLE OF CONTENTS LIST OF ILLUSTRATIONS Section & Figure Page 1 — INTRODUCTION TYPICAL NETWORK, LOCAL TERMINAL CONTROL ..............1-7 TYPICAL NETWORK, REMOTE TERMINAL CONTROL USING MODEMS ........1-7 TYPICAL NETWORK, LOCAL TERMINAL CONTROL USING PMC-100s WITH DIAL BACKUP..1-8 TYPICAL NETWORK, REMOTE TERMINAL CONTROL USING PMC-100s WITH DIAL BACKUP ..
  • Page 14 TABLE OF CONTENTS LIST OF ILLUSTRATIONS (Cont.) Section & Figure Page 3-15 RECEIVE LEVEL SCREEN......................3-27 3-16 DS0 DIAGNOSTICS SCREEN......................3-28 3-17 CSU CONFIGURATION SCREEN....................3-32 3-18 MAINTENANCE SCREEN......................3-36 4 — TESTS TROUBLE DIAGNOSTIC FLOWCHART..................4-3 DS1 LINE LOOPBACK FUNCTION....................4-4 DS1 NETWORK INTERFACE LOOPBACK FUNCTION ...............4-5 DS1 TEST LOOPBACK FUNCTION....................
  • Page 15 TABLE OF CONTENTS LIST OF TABLES Section & Table Page 1 — INTRODUCTION HOUSINGS FOR DataComm 551 AND RELATED PRODUCTS.............1-3 EQUIPMENT LIST........................... 1-4 2 — INSTALLATION OPTION APPLICATION NOTES (2 Sheets)................... 2-6 CSU ADDRESS SELECTION ......................2-10 3 — OPERATION STATUS LINE INDICATORS (2 Sheets)..................3-11 4 —...

  • Page 17: Description

    • The DataComm 551 can be pre-equalized for line lengths of up to 655 feet (199.6 m) on the customer equipment side. • The DataComm 551 can perform automatic Line Build-Out (signal at-...

  • Page 18: Diagnostics

    FourPak, GDC TriPak, and Universal System Shelf installations, us- ing a Telco-provided current source) • The DataComm 551 can can be configured as a slave CSU, limiting the configuration changes and diagnostics available via the Supervisory terminal. This prevents actions which could disrupt service.

  • Page 19: Applications

    • DS0 Remote Test • DS0 Remote Test with Self-Test The DataComm 551 also allows the user to set the time and date, display the firmware revision level, and reset the CSU. Note that some of these functions require the use of the Supervisory ter- minal.
  • Page 20 INTRODUCTION TABLE 1-2. EQUIPMENT LIST Description GDC Part No. GDC DataComm 551 Intelligent CSU, standalone single-slot enclosure model DE-7, 117 V ac 048A018-001 GDC DataComm 551 Intelligent CSU, rackmount pc card 048P037-001 Mounting Enclosures and Shelves DataComm FourPak Enclosure model DFP-11, standalone, 117 V ac...
  • Page 21 INTRODUCTION TABLE 1-2. EQUIPMENT LIST (Cont.) Description GDC Part No. Optional Equipment Supervisory terminal (customer-provided) Modem (customer-provided) PMC-100 Performance Monitor Card 048P038-001 60 mA dc constant current source for providing span power (Telco-provided) Applicable Instruction Manuals Instruction Manual for GDC TriPak Shelf 010R355-000 Instruction Manual for 10 1/2-Inch DataComm Modem Shelf Model DS-1 010R310-000...

  • Page 22: Backward Compatibility

    Figure 1-4 illustrates a small network and a terminal utilizing modems for remote access, while Figure 1-5 illustrates a larger network. The PMC-100 also, on request, polls each DataComm 551 in the network for its alarm status and displays this on the Supervisory terminal.
  • Page 23 SITE B DataComm 551 DataComm 551 EQUIPMENT EQUIPMENT NETWORK SUPERVISORY TERMINAL SUPERVISORY TERMINAL FOR DataComm 551 AT SITE A FOR DataComm 551 AT SITE B FIGURE 1-1. TYPICAL NETWORK, LOCAL TERMINAL CONTROL SITE A SITE B DataComm 551 DataComm 551 EQUIPMENT...
  • Page 24 INTRODUCTION NEW YORK BOSTON DATA DIAL BACKUP SHOULD PRIMARY ROUTE FOR DATA CHANNEL T1 LINK FAIL CHANNEL DIAGNOSTICS VIA T1 DataComm DataComm PMC-100 PMC-100 MODEM MODEM SLAVE MASTER SWITCHED NETWORK NOT USED LEGEND NE = NETWORK ELEMENT P= PCL PORT S= SUPERVISORY PORT M=MODEM PORT SUPERVISORY TERMINAL...
  • Page 25 INTRODUCTION NEW YORK BOSTON DATA DIAL BACKUP SHOULD PRIMARY ROUTE FOR DATA CHANNEL T1 LINK FAIL DIAGNOSTICS VIA T1 CHANNEL DataComm DataComm PMC-100 PMC-100 MODEM MODEM SLAVE MASTER SWITCHED NETWORK LEGEND NOT USED NE = NETWORK ELEMENT P= PCL PORT S= SUPERVISORY PORT M=MODEM PORT SUPERVISORY TERMINAL...

  • Page 26: And Dial Backup

    INTRODUCTION TO SWITCHED NETWORK FOR OPTIONAL DIAL BACKUP TO SWITCHED NETWORK FOR OPTIONAL DIAL BACKUP TO SWITCHED NETWORK FOR OPTIONAL DIAL BACKUP TO SWITCHED NETWORK FOR OPTIONAL DIAL BACKUP SUPERVISORY TERMINAL FIGURE 1-5. TYPICAL NETWORK, REMOTE TERMINAL CONTROL USING PMC-100s WITH EXPANSION AND DIAL BACKUP 1-10...

  • Page 27: Installation

    Test to verify normal operation. Refer to Section 4 for instructions on per- forming this test. First verify that the options are set as shown in Figure 2-1, and perform the test on the DataComm 551 before it is connected to anything except ac power.
  • Page 28 INSTALLATION REAR EDGE OF PC CARD SPAN NETD4 EQESF LOOP MANF B8ZS SLAVE ALBO A T T FRONT PANEL NOTE: OPTIONS ARE SELECTED AS SHIPPED FROM THE FACTORY. FIGURE 2-1. OPTION LOCATION...
  • Page 29 DataComm Modem Shelf. DataComm 551 can be installed in any slot; however, for each DataComm 551, one adapter cable and coupler (P/Ns 027H242-X04 and 209-038-002), or cable P/N 022H024-XXX, are required to connect the T1 line. GDC TriPak Shelf (models TPS-1 and TPS-2)
  • Page 30 INSTALLATION CAUTION: DISCONNECT POWER CABLE AND PHONE CONNECTIONS BEFORE REMOVING COVER. WITH FRONT OF UNIT FACING LEFT, TURN SCREW TO RELEASE COVER. LIFT RIGHT END OF COVER UPWARD. (FOR DUAL-CARD PRODUCTS, SPREAD OUT THE SIDES OF THE COVER TO CLEAR THE UPPER CARD.) SLIDE COVER TO LEFT WITH AN UPWARD MOTION.

  • Page 31: Master/Slave Csu Option

    OPTION SELECTION The field-selectable options adapt the DataComm 551 to a variety of con- figurations, as well as enable or disable certain features and tests. These options are selected by the positioning of switches and jumper straps on the pc card.
  • Page 32 Inband Loop- DS1 Line Loop S5-6 OFF * DataComm 551 starts or stops a DS1 Line Loop test back Code Test when the appropriate inband loopback code is de- Type tected (when S6-8 is OFF, and only with ESF framing on the network side).
  • Page 33 TABLE 2-1. OPTION APPLICATION NOTES (Cont.) Switch (S) or Option Selection Jumper (X) Position Description Inband Loop- Unframed S5-7 OFF * DataComm 551 sends unframed inband loopback back Code codes. Framing Framed S5-7 DataComm 551 sends framed inband loopback codes. Ones Density 15 zeros S5-8...
  • Page 34 Selects frame and signal grounds isolated by 100Ω. Power to span Disabled LOOP * DataComm 551 loops power to the span. Enabled DataComm 551 provides power to the span (requires Telco-provided external 60 mA dc con- stant current source). Available only in DataComm FourPak, GDC TriPak, and Universal System Shelf installations.

  • Page 35: Option Selection In An Installation With A Mau-1A

    The major improvement is PMC-100 support, eliminating the need for us- ing MAU-1As and fallback switches for Supervisory terminal communi- cations. When replacing an older DataComm 551 with a newer one, note the following option switch changes: Switch...
  • Page 36 INSTALLATION TABLE 2-2. CSU ADDRESS SELECTION CSU Address = AD7/AD6/AD5/AD4/AD3/AD2/AD1/AD0 (Option Switches S4-8 to S4-1) 0 = Switch OFF; 1 = Switch ON 0=00000000 51=00110011 102=01100110 153=10011001 204=11001100 1=00000001 52=00110100 103=01100111 154=10011010 205=11001101 2=00000010 53=00110101 104=01101000 155=10011011 206=11001110 3=00000011 54=00110110 105=01101001 156=10011100 207=11001111...
  • Page 37 NOTE 2: THIS OPTION IS NOT AFFECTED BY CONFIGURATION FROM THE SUPERVISORY TERMINAL. NOTE 3: REFER TO OPTION SELECTION FOR USE OF THIS SWITCH WHEN REPLACING AN OLDER DataComm 551 WITH A NEWER ONE. FIGURE 2-3. OPTION SWITCH AND JUMPER SELECTIONS (Sheet 1 of 2)
  • Page 38 NOTE 2: THIS OPTION IS NOT AFFECTED BY CONFIGURATION FROM THE SUPERVISORY TERMINAL. NOTE 3: REFER TO OPTION SELECTION FOR USE OF THIS SWITCH WHEN REPLACING AN OLDER DataComm 551 WITH A NEWER ONE. FIGURE 2-3. OPTION SWITCH AND JUMPER SELECTIONS (Sheet 2 of 2)
  • Page 39 INSTALLATION NEW YORK BOSTON DATA PRIMARY ROUTE FOR DATA CHANNEL DIAGNOSTICS VIA T1 CHANNEL DataComm DataComm PMC-100 PMC-100 SLAVE MASTER LEGEND NE= NETWORK ELEMENT P= PCL PORT S= SUPERVISORY PORT M=MODEM PORT SUPERVISORY TERMINAL FIGURE 2-4. IN-BAND COMMUNICATION PATH NEW YORK BOSTON PRIMARY ROUTE FOR DIAL BACKUP FOR...

  • Page 40: Electrical Connections

    Supervisory terminal, and primary power connections to the DataComm 551. Equipment Connection Connect the customer equipment (T1 multiplexer) to the DataComm 551 as described below. Unless otherwise noted, the customer equipment interface is a 25-pin fe- male subminiature-D connector located on the rear panel, and you should...

  • Page 41: Network Interface Connection

    NESS EQUIP 4, as shown in Figure 2-10. Network Interface Connection Connect the network (T1 line) to the DataComm 551 as described below. Unless otherwise noted, the network interface is an RJ48C jack located on the rear panel. For other than a DataComm Modem Shelf installation, you must use ei- ther GDC cable P/N 022H024-XXX (RJ48C plug-to-plug) or 022H021-XXX (RJ48C plug-to-terminal lugs) to connect the network to the CSU.
  • Page 42 Serial No. CONTROL LINE Business Equipment Auxiliary 117V 60Hz 0.2 Amps GENERAL DATACOMM Middlebury, Ct. EQUIPMENT CONNECTOR (25-PIN FEMALE) CONNECTS SUPERVISORY PORT CONNECTOR (25-PIN MALE) THE MULTIPLEXER TO THE CSU. CONNECTS THE SUPERVISORY TERMINAL TO THE CSU. PIN NO. FUNCTION DIRECTION PIN NO.
  • Page 43 RECEIVE DATA (RING) FROM CSU CARRIER DETECT FROM CSU THIS PORT IS ENABLED ONLY WHEN PMC-100 OPERATION IS DISABLED. WHEN INSTALLING A DataComm 551 IN SLOT FOUR, PLACE JUMPER OVER COLUMN OF PINS LABELED T1. FIGURE 2-7. DataComm FOURPAK ENCLOSURE INSTALLATION 2-17...
  • Page 44 INSTALLATION EQUIPMENT CONNECTOR (25-PIN FEMALE) CONNECTS THE MULTIPLEXER TO THE CSU. PIN NO. FUNCTION DIRECTION FRAME GROUND SEND DATA (TIP) TO CSU RECEIVE DATA (TIP) FROM CSU SEND DATA (RING) TO CSU RECEIVE DATA (RING) FROM CSU NETWORK INTERFACE CONNECTOR (RJ48C) CONNECTS THE NETWORK TO THE CSU.
  • Page 46 INSTALLATION EQUIPMENT CONNECTOR (25-PIN FEMALE, LABELED X BUS CONNECTORS FOR COMMUNICATION BETWEEN BUSINESS EQUIP 1 - BUSINESS EQUIP 4 (CONNECTS PMC-100s. REFER TO PMC-100 MANUAL FOR DETAILS. THE MULTIPLEXER TO THE CSU. PIN NO. FUNCTION DIRECTION FRAME GROUND SEND DATA (TIP) TO CSU RECEIVE DATA (TIP) FROM CSU...
  • Page 47 GDC TriPak Shelf Connect the network to the DataComm 551 by means of the jacks labeled J1 through J3, as shown in Figure 2-9. For each DataComm 551 you in- stall, you must install the appropriate rear panel option jumper in the T1.5 position.
  • Page 48 RECEIVE DATA (TIP) MA OUT RECEIVE DATA (RING) SEND DATA (TIP) MA IN SEND DATA (RING) DataComm 551 CSU A. CSU CONFIGURED TO LOOP SPAN POWER (LOOP SELECTED FOR JUMPER X3) RECEIVE DATA (TIP) MA OUT RECEIVE DATA (RING) SEND DATA (TIP)

  • Page 49: Supervisory Terminal Connection

    CSUs in the network. The Supervisory terminal can be any ANSI X3.64-compatible ASCII terminal that supports asynchronous EIA/TIA-232- E communications. The DataComm 551 Supervisory port supports: • data rates from from 2400 to 19,200 bps • one start bit •...
  • Page 50 Unless otherwise noted, the Supervisory port is a 25-pin EIA/TIA-232-E male connector located on the rear panel, and the terminal interface ca- ble must be terminated on the DataComm 551 end in a DB25S connector and on the other end in a connector compatible with the Supervisory ter- minal.
  • Page 51 INSTALLATION SITE A SITE B DataComm 551 DataComm 551 EQUIPMENT EQUIPMENT NETWORK DB25S DB25S SUPERVISORY DB25P DB25P PORT MODEM MODEM PUBLIC SWITCHED SERVICE CENTER NETWORK DB25P MODEM SUPERVISORY TERMINAL FOR BOTH DataComm 551s FIGURE 2-12. SUPERVISORY TERMINAL MODEM APPLICATION 2-25...

  • Page 52: Primary Power Connection

    INSTALLATION At each CSU site: • Connect the modem to the DataComm 551 by means of the 25-pin EIA/TIA-232-E male Supervisory port connector on the DataComm 551 rear panel, as shown in the appropriate figure. The interface cable must be terminated on the modem end in a DB25P connector and on the DataComm 551 end in a DB25S connector.

  • Page 53: Datacomm Fourpak Enclosure Installation

    The Telco continuously monitors the T1 link and the equipment connected to it. Before connecting the DataComm 551 to the network, or disconnecting it, the Telco should be notified. DataComm Enclosure Installation The DataComm Enclosure is equipped with a captive ac power cord ter- minated in a molded three-prong plug.

  • Page 55: Operation

    PROCEDURES The Supervisory terminal is used to configure, test, and maintain the DataComm 551 to which it is connected. It is also used to monitor the net- work Performance Reports provided by the Central Office. The functions of the Supervisory terminal are menu-oriented: there is a MAIN MENU...
  • Page 56 OPERATION EQUIPMENT LOW AVERAGE DENSITY (RED) BLINKS WHEN THE EQUIPMENT SIGNAL'S AVERAGE ONES DENSITY IS LESS THAN THAT SELECTED WITH THE ONES DENSITY OPTION. LIGHTS WHEN CONDITION PERSISTS. OFF WHEN EQUIP NS INDICATOR IS ON. EQUIPMENT ZEROS (RED) EQUIPMENT NO SIGNAL (RED) BLINKS WHEN EXCESSIVE LIGHTS WHEN EQUIPMENT SIGNAL HAS CONSECUTIVE CONSECUTIVE ZEROS ARE RECEIVED...

  • Page 57: Front Panel Access Test Jacks

    OPERATION CSU SIGNAL MONITOR INSERT TEST CABLE TO MONITOR CSU-TO-EQUIPMENT SIGNAL (PATH IS NOT BROKEN). TEST EQUIPMENT RECEIVES CSU OUTPUT. CSU SIGNAL INPUT INSERT TEST CABLE TO BREAK EQUIPMENT-TO-CSU SIGNAL PATH. PERMITS TEST EQUIPMENT TO TRANSMIT SIGNAL TO CSU. CSU SIGNAL OUTPUT INSERT TEST CABLE TO BREAK CSU-TO-EQUIPMENT SIGNAL PATH.
  • Page 58 OPERATION REMOTE TEST ENGAGE TO PLACE THE CSU IN REMOTE TEST (RT). SELF TEST ENGAGE TO PLACE THE CSU IN END-TO-END SELF-TEST (ST). USE WITH LT FOR LOCAL TEST WITH SELF-TEST. USE WITH RT FOR REMOTE TEST WITH SELF-TEST. LOCAL TEST ENGAGE TO PLACE THE CSU IN LOCAL TEST (LT).

  • Page 59: Main Menu

    OPERATION DS1 DIAGNOSTICS MENU EACH OF THESE SELECTIONS PROVIDES A SCREEN DS0 DIAGNOSTICS SCREEN MAIN MENU MAINTENANCE SCREEN CSU CONFIGURATION SCREEN FIGURE 3-4. MENU ORGANIZATION...
  • Page 60 OPERATION provide this access. Once the Supervisory terminal is communicating with the CSU, its operation is the same regardless of the means used to connect to it. That is, the Supervisory terminal appears to be connected di- rectly to the CSU. The following paragraphs describe the procedures used to access the CSU.

  • Page 61: Master/Slave Csu Option

    OPERATION CAUTION Do not attempt to access another CSU or the master PMC-100 while a CSU is waiting for confirmation of your last entry (indicated by the prompt Are You Sure? (Y/N) displayed at the bottom of the screen). If you do, you must repeat the process of accessing it.

  • Page 62: The Log-On Screen

    OPERATION The Log-On Screen When you access the CSU, or on CSU power-up or reset, the DataComm 551 log-on screen is displayed (see Figure 3-5). It displays the following in- formation: • system date (D D - M M M - Y Y ) •...

  • Page 63: Display Information

    OPERATION The firmware revision level identifies the firmware version (the system software contained in EPROMs). A memory status message is Passed (message is on steady) or Failed (message is flashing), and indicates whether the memory passed certain tests. A RAM failure is also indicated by flashing front panel indicator BPV, and a ROM failure is also indicated by flashing front panel indi- cator LB.

  • Page 64: Using The Keyboard

    OPERATION • current menu or screen name • system date and time • status line • CSU address number The status line reflects the status of the front panel indicators and switches, and provides additional information. For front panel switches, a period (.) indicates that the switch is disengaged, and an X indicates that it is engaged.
  • Page 65 OPERATION TABLE 3-1. STATUS LINE INDICATORS Equivalent Status Line Front Panel Indicator Name Name Description Network Indicators SYN * SYN * Network Synchronization — indicates whether the CSU is (.) or is not (X) syn- chronized with network framing. (In Unframed Mode, there are no network framing bits, so synchronization with the network cannot be assured and it is not monitored.) Network No Signal —...
  • Page 66 OPERATION TABLE 3-1. STATUS LINE INDICATORS (Cont.) Equivalent Status Line Front Panel Indicator Name Name Description Pushbutton Switches Local Test — indicates whether the LT pushbutton is engaged (X) or disengaged (.). Self-Test — indicates whether the ST pushbutton is engaged (X) or disengaged (.). Also indicates whether DS0 Self Test or DS0 Loopback (at the local CSU) is (X) or is not (.) active.
  • Page 67 OPERATION NOTE In Unframed Mode, the One Hour Report, Twenty-Four Hour Report and Scheduled Performance Report selections are removed from the DS1 DIAGNOSTICS menu (the entire bandwidth is used for customer pay- load, so network performance is not measured and these screens do not apply).

  • Page 68: Alarm Counts Screen

    When you use the PMC-100 to perform the Scan Network Elements func-tion, a 551 with alarm conditions reports to the PMC-100 the number of Major and Minor Alarms but does not report specific alarms. You must review the ALARM COUNTS screen to determine which alarms exist.
  • Page 69 * These alarms appear on the status line. Because they indicate current status, they may have cleared by the time you go from the PMC-100’s Scan Network Elements screen to the 551 reporting the alarm. Interval The displayed time interval indicates the number of hours (nn Hrs) and minutes (nn Mins) since the CSU has been powered up or reset, or since the alarms have been cleared.
  • Page 70 OPERATION Network Alarm Indication This is a count of the number of times the CSU receives an AIS from the network (the counter increments only when the alarm is removed). The status line and front panel AIS indicators reflect whether the CSU is re- ceiving an AIS.

  • Page 71: One Hour Report Screen

    OPERATION tion of the Ones Density option (maximum of 15 or 39 zeros), defining the maximum number of consecutive zeros transmitted before a "one" is in- serted. The status line and front panel 0'S indicators reflect the current status of excessive zeros. DTE Low Average Density This is a count of the number of times the CSU receives an equipment signal with an average pulse density less than that selected with the Ones...
  • Page 72 OPERATION Current Interval Time This is the number of seconds into the current 15-minute interval. The maximum count is 900. Last 24 Hours ES/FS This is an averaged summary of the ES and FS counts for the last 24 hours. The maximum count is 65535. If this number is exceeded, the counter freezes at this number until cleared using the Initialize CSU Reg- isters command described below.

  • Page 73: Twenty-Four Hour Report Screen

    OPERATION terval. When 15 minutes passes, this data is shifted down into the 4th 15- Minutes counter and is replaced by the data from the 2nd 15-Minute counter. 4th 15-Minutes ES/FS This is a count of the ESs and FSs for the fourth most recent 15-minute in- terval.
  • Page 74 OPERATION 1st Hour ES/FS This is a count of the ESs and FSs for the most recent hour. When one hour passes, this data is shifted down into the 2nd Hour counter and is re- placed by the data from the Current Interval counter. The maximum count for this and the other one hour counters is 3600 (60 minutes = 3600 sec- onds).

  • Page 75: The Ds1 Diagnostics Menu

    OPERATION 24th Hour ES/FS This is a count of the ESs and FSs for the 24th most recent hour. When one hour passes, this data is discarded and is replaced by the data from the 23rd Hour counter. SCHEDULED PERFORMANCE REPORT SCREEN This function displays the information that the CSU makes available to the network upon its request for a Scheduled Performance Report.
  • Page 76 OPERATION Controlled Slip Event An asterisk (*) indicates that during this one-second interval one or more controlled slip events occurred. Active Payload Loop An asterisk (*) indicates that during this one-second interval the CSU was in a payload loopback condition (looping back toward the network frames consisting of the received 192 information bits [the payload] plus its own framing, CRC-6, and Data Link bits [the F-bits]).

  • Page 77: Ds1 Self Test Screen

    OPERATION DS1 SELF TEST SCREEN This function causes the CSU to generate and verify a test pattern, simi- lar to the DS1 Self-Test performed by using front panel switches LT and ST (described in Section 4). However, this test provides additional control and more test result information.
  • Page 78 OPERATION User Pattern This displays the test pattern selected with the Set User Pattern (P) func- tion. If no pattern has been selected, the pattern is Default. Test Frame This displays the framing type selected with the Framing (F) function. It is FRAMED or UNFRAMED.

  • Page 79: Loopbacks Screen

    OPERATION and then press RETURN. The pattern is displayed in User Pattern. This pattern is retained when you exit this screen, but lost if the CSU is reset or powered down. Framing This function selects a framed or unframed test pattern. Press F to choose one (displayed in Test Frame).
  • Page 80 OPERATION CAUTION a. A slave CSU displays the warning message W A R N - ING: Interfering To Inband Communication when the user attempts to perform any loopback: Proceeding with the diagnostic can result in inaccu- rate data on the terminal or complete loss of com- munication.

  • Page 81: Receive Level Screen

    OPERATION RECEIVE LEVEL SCREEN This function displays information about the Line Build-Out option and the network signal. To use this function, press R. Figure 3-15 illustrates the RECEIVE LEVEL screen. Line Build-out This displays the amount of manual Line Build-Out (LBO) selected, 0.0 dB or 15.0 dB.

  • Page 82: The Ds0 Diagnostics Screen

    OPERATION The DS0 Diagnostics Screen The Supervisory terminal can be used to control several channel-level (DS0) diagnostic tests. Figure 3-16 illustrates the functions available through this screen. Only one test, on one of the 24 channels, can be performed at a time. A DS0 diagnostic affects only the selected channel. CAUTION All DS0 diagnostic functions can be selected only via the Supervisory terminal, and those selected for the...
  • Page 83 OPERATION Select Test Pattern This function selects and displays the test pattern used in the BIT ER- ROR TEST mode. To use this function, press S to step through the three test patterns available: 511-bit test pattern 2047 2047-bit test pattern Quasi-Random Signal (QRS) test pattern The test pattern selection is retained when you exit this screen, and when the CSU is reset or powered down.

  • Page 84: The Csu Configuration Screen

    Screen The Supervisory terminal can be used to display and configure nearly all of the DataComm 551 options that can be selected via option switches on the pc card. The Supervisory terminal can also be used to restore the factory default configuration for the CSU. Figure 3-17 illustrates the func- tions available through the CSU CONFIGURATION screen.
  • Page 85 OPERATION tempts to configure it, the CSU displays the message Invalid Mode at the bottom of the screen. NOTE If Local Option Override is enabled (option switch S7-7 is ON), configuration via the Supervisory terminal is not allowed. When the CSU is configured as a slave CSU, the following options cannot be changed via the Supervisory terminal, but their status is displayed: •...
  • Page 86 OPERATION Use the Update Defaults function to set all options to their factory default values, or use the individual functions to set each option as required. To set an option, press the letter shown to the left of it. Each time you press the letter, you see a different choice.
  • Page 87 OPERATION DTE Code This sets the Line Code option for the equipment side to A M I (Alternate Mark Inversion, with no bipolar violations) or B8ZS (Bipolar with 8 Zero Substitution, with bipolar violations). Which one you choose depends pri- marily on the design of the T1 link: all equipment must be compatible with the AMI line code, and some equipment may not be compatible with the B8ZS line code.
  • Page 88 OPERATION NOTE Do not enable Auto Framing for both CSUs on a link. NET Frame This sets the Network Frame Format option for the network side to AUTO (Auto Framing), M A N (manually-set framing) or NONE (no framing), and one of the following framing types: ESF (Extended Superframe Format) or D4 (D4 Superframe Format).

  • Page 89: The Maintenance Screen

    OPERATION ILB Frame This sets the Inband Loopback Code Framing option to UNFRAMED (CSU transmits unframed inband loopback codes) or FRAMED (CSU transmits framed inband loopback codes), when a DS1 Remote Test is started. The default setting is UNFRAMED. (This option is also set via option switch S5-7.) (In Unframed Mode, this function is always set to UNFRAMED.) Line Build-Out...
  • Page 90 OPERATION Set Date This function sets the CSU date. The date is entered in the format: mm-dd-yy where mm is the month (January = 01, etc.), dd is the day of the month, and yy is the year (1989 = 89). Separate each with a character such as a hyphen, comma, period, diagonal, or space.
  • Page 91 OPERATION Reset CSU This function resets the CSU. Resetting the CSU disrupts data transmis- sion and creates alarm conditions for the Central Office, so use it with care. Resetting the CSU returns you to the log-on screen and clears the date and time, so you must set them after a reset.

  • Page 92: Tests

    OVERVIEW This section describes the tests that can be performed with the DataComm 551 after installation, whenever the operation of it must be checked, or when problems in the data communications system must be isolated (see Figure 4-1). Some tests prevent normal operation of the CSU and should be performed only when the CSU is not in use, while others have no impact on operation and can be performed anytime.

  • Page 93: Ds0 Remote Test

    TESTS • DS0 Remote Test • DS0 Remote Test with Self-Test • DS0 Self-Test (including DS0 End-to-End Self-Test) The tests are controlled in one or more of the following ways: via the front panel pushbutton switches, the Supervisory terminal, or loopback codes received from the network.
  • Page 94 TESTS START PERFORM LOCAL TEST WITH SELF-TEST FAIL PASS PASS LOCAL CSU PERFORM PROBLEM LOCAL TEST FAIL? FAIL PASS PASS LOCAL EQUIPMENT OR EQUIPMENT-CSU PERFORM CONNECTION PROBLEM LINE LOOP FAIL? FAIL PASS PASS LOCAL CSU OR CSU-LINE PERFORM CONNECTION PROBLEM TEST LOOP FAIL? PERFORM REMOTE TEST OR REMOTE TEST...

  • Page 95: Ds1 Loopback Functions

    TESTS DS1 LOOPBACK FUNCTIONS The DS1 Line Loopback and DS1 Test Loopback functions allow the sig- nal received from the network to be looped through the CSU's circuitry and transmitted back toward the network. These functions in themselves are not tests, but are used in conjunction with other DS1 diagnostic tests. The DS1 Network Interface Loopback function allows the signal received from the network to be looped back toward the network at the Telco-pro- vided DS1 Interface Connector.

  • Page 96: Ds1 Network Interface Loopback Function

    CAUTION When connected to a DS1 Interface Connector, the DataComm 551 must be configured for manual Line Build-Out, with 0 dB attenuation. The DS1 Network Interface Loopback function can be activated and deac- tivated remotely via the Supervisory terminal or by the Telco, using loop- back codes as defined in Bellcore TR-TSY-000312.

  • Page 97: Ds1 Test Loopback Function

    TESTS DS1 Test Loopback Function The DS1 Test Loopback (TLB) function, illustrated in Figure 4-4, allows the signal received from the network to be looped through as much as is practical of the CSU's circuitry and transmitted back toward the network. This tests everything on the network side up to and including the CSU.

  • Page 98: Ds1 Diagnostics

    TESTS DS1 DIAGNOSTICS The DS1 diagnostics described below include link-level diagnostic tests that affect the entire T1 link, or the DS1 (Digital Signal Level 1). Use these tests when you suspect that a problem is impairing data on all channels. Some of these tests can be controlled only via the Supervisory terminal, while others can also be controlled via the front panel switches.

  • Page 99: Ds1 Local Test

    TESTS DS1 Local Test DS1 Local Test (LT), illustrated in Figure 4-6, loops a locally-generated test message through the CSU and back to the test equipment for verifica- tion. As much as is practical of the CSU's circuitry is utilized in this test. During this test, data is also transmitted to the T1 link, with pulse den- sity constraints, but data is not received from the line.

  • Page 100: Ds1 Local Test With Self-Test

    TESTS DS1 Local Test with Self-Test DS1 Local Test with Self-Test, illustrated in Figure 4-7, transmits an in- ternally-generated test pattern through the CSU to test the CSU. During this test, data is also transmitted to the T1 link, with pulse density con- straints, but data is not received from the equipment or the line.

  • Page 101: Ds1 Network Interface Loopback

    CAUTION When connected to a DS1 Interface Connector, the DataComm 551 must be configured for manual Line Build-Out, with 0 dB attenuation. This test can only be controlled locally via the Supervisory terminal NI Loop test.

  • Page 102: Ds1 Network Interface Loopback With Self-Test

    CAUTION When connected to a DS1 Interface Connector, the DataComm 551 must be configured for manual Line Build-Out, with 0 dB attenuation. This test can only be controlled locally via the Supervisory terminal NI Loop test and Self-Test. To perform this test, refer to Table 4-5.

  • Page 103: Ds1 Remote Test

    TESTS DS1 Remote Test DS1 Remote Test (RT) activates the remote CSU's DS1 Line Loopback function (illustrated in Figure 4-10) or DS1 Test Loopback function (Figure 4-11), depending on which one is enabled in the remote CSU. This tests both CSUs and the T1 link by transmitting a locally-generated test message through the local CSU to the remote CSU and looping it back to the test equipment for verification.
  • Page 104 TESTS CSU OUT EQUIPMENT EQUIPMENT CSU IN NETWORK LOCAL CSU REMOTE CSU HAS LLB ENABLED TEST EQUIPMENT FIGURE 4-10. DS1 REMOTE TEST WITH LINE LOOPBACK CSU OUT EQUIPMENT EQUIPMENT CSU IN NETWORK LOCAL CSU REMOTE CSU HAS TLB ENABLED TEST EQUIPMENT FIGURE 4-11.

  • Page 105: Ds1 Remote Test With Self-Test

    TESTS DS1 Remote Test with Self-Test DS1 Remote Test with Self-Test activates the remote CSU's DS1 Line Loopback function (illustrated in Figure 4-12) or DS1 Test Loopback func- tion (Figure 4-13), depending on which one is enabled in the remote CSU. This tests both CSUs and the T1 link by transmitting a local CSU-gener- ated test pattern to the remote CSU and looping it back for verification.
  • Page 106 TESTS EQUIPMENT EQUIPMENT NETWORK LOCAL CSU REMOTE CSU HAS LLB ENABLED TPG = TEST PATTERN GENERATOR TPR = TEST PATTERN RECOGNIZER FIGURE 4-12. DS1 REMOTE TEST WITH LINE LOOPBACK AND SELF-TEST EQUIPMENT EQUIPMENT NETWORK LOCAL CSU REMOTE CSU HAS TLB ENABLED TPG = TEST PATTERN GENERATOR TPR = TEST PATTERN RECOGNIZER FIGURE 4-13.

  • Page 107: Ds1 Self-Test

    TESTS DS1 Self-Test DS1 Self-Test (ST) causes the CSU to generate and verify a test pattern. The test pattern is selected via option switch S5-4 or the Supervisory ter- minal. DS1 Self-Test can be used with DS1 Local Test (refer to DS1 Local Test with Self-Test), DS1 Remote Test (refer to DS1 Remote Test with Self- Test) or DS1 Network Interface Loopback (refer to DS1 Network Interface Loopback with Self-Test) to test one CSU, or alone as a DS1 End-to-End...
  • Page 108 TESTS EQUIPMENT EQUIPMENT NETWORK LOCAL CSU REMOTE CSU TPG = TEST PATTERN GENERATOR TPR = TEST PATTERN RECOGNIZER FIGURE 4-14. DS1 END-TO-END SELF-TEST 4-17...

  • Page 109: Ds1 Test Loop

    TESTS DS1 Test Loop DS1 Test Loop, illustrated in Figure 4-15, activates the local CSU's DS1 Test Loopback function. This tests the local CSU and the T1 link by transmitting a remotely-generated test message through the remote CSU to the local CSU and looping it back to the test equipment for verification. This test can be controlled only via the Supervisory terminal, using the DS1 Test Loop function.

  • Page 110: Ds0 Diagnostics

    TESTS DS0 DIAGNOSTICS The DS0 diagnostics described below include channel-level diagnostic tests that affect a single channel, or a DS0 (Digital Signal Level 0). Use these tests when you suspect that a problem is impairing data only on an isolated channel. Only one test, on one of the 24 channels, can be per- formed at a time.
  • Page 111 TESTS EQUIPMENT EQUIPMENT NETWORK LOCAL CSU REMOTE CSU ONLY THE SELECTED CHANNEL DDM = DS0 DELAY MEASUREMENT CIRCUITRY IS AFFECTED FIGURE 4-16. DS0 CIRCUIT DELAY MEASUREMENT TEST 4-20...

  • Page 112: Ds0 Remote Test

    TESTS DS0 Remote Test DS0 Remote Test, illustrated in Figure 4-17, tests both CSUs and the T1 link by transmitting, on the selected channel, a locally-generated test message through the local CSU to the remote CSU and looping it back to the test equipment for verification.

  • Page 113: Ds0 Remote Test With Self-Test

    TESTS DS0 Remote Test with Self-Test DS0 Remote Test with Self-Test, illustrated in Figure 4-18, tests both CSUs and the T1 link by transmitting, on the selected channel, a local CSU- generated test pattern to the remote CSU and looping it back for verifica- tion.

  • Page 114: Ds0 Self-Test

    TESTS DS0 Self-Test DS0 Self-Test causes the CSU to generate and verify a test pattern on the selected channel. The test pattern is selected via the Supervisory termi- nal. DS0 Self-Test can be used with DS0 Remote Test (refer to DS0 Remote Test with Self-Test) to test primarily the T1 link and the remote CSU, or alone as DS0 End-to-End Self-Test to also test the local CSU.
  • Page 115 TESTS EQUIPMENT EQUIPMENT NETWORK LOCAL CSU REMOTE CSU ONLY THE SELECTED CHANNEL TPG = TEST PATTERN GENERATOR TPR = TEST PATTERN RECOGNIZER IS AFFECTED FIGURE 4-19. DS0 END-TO-END SELF-TEST 4-24...
  • Page 116 TESTS DS1 LOOPBACK FUNCTIONS A. DS1 NETWORK INTERFACE LOOPBACK FUNCTION B. DS1 LINE LOOPBACK FUNCTION C. DS1 TEST LOOPBACK FUNCTION EQUIPMENT EQUIPMENT NETWORK DS1 INTERFACE CONNECTOR DS1 LOOPBACK TESTS A. DS1 LINE LOOP B. DS1 TEST LOOP TEST EQUIPMENT NETWORK EQUIPMENT LOCAL CSU REMOTE CSU...

  • Page 117: Ds0 End-To-End Self-Test

    TESTS DS0 DIAGNOSTICS A. DS0 CIRCUIT DELAY MEASUREMENT TEST EQUIPMENT EQUIPMENT NETWORK LOCAL CSU REMOTE CSU ONLY THE SELECTED CHANNEL IS AFFECTED B. DS0 REMOTE TEST C. DS0 REMOTE TEST WITH SELF-TEST EQUIPMENT EQUIPMENT NETWORK TERMINAL (OR TEST EQUIPMENT) LOCAL CSU REMOTE CSU ONLY THE ON SELECTED CHANNEL...

  • Page 118: Technical Assistance Procedure

    TESTS TECHNICAL ASSISTANCE PROCEDURE For technical assistance, customers should call DataComm Service Corporation at 203-598-7526. In Canada: General DataComm (Canada) Ltd. Service and Repair Facility 1790 Beaulac Street St. Laurent, Montreal, Quebec H4R 1W8 Telephone: 1-514-336-5454 TWX: 610-421-3221 Telex: 05824085 In the United Kingdom, contact the GDC area manager at: General DataComm (U.K.) Ltd.

  • Page 119: Training

    TESTS In Latin America: General DataComm, International 1579 Straits Turnpike P.O. Box 1299 Middlebury, Connecticut 06762-1299 Telephone: 203-574-1118 Telex: 7400905 Fax: 203-758-9518 To return a unit for repair, if so authorized by GDC, use the return tag and address the package: Product Repair Department General DataComm, Inc.

  • Page 120: Appendix A - Technical Information

    APPENDIX A TECHNICAL INFORMATION TECHNICAL CHARACTERISTICS Item Characteristic Physical PC card assembly Height 7/8 in (2.22 cm) Width 10 1/2 in (26.67 cm) Depth 10 3/4 in (27.31 cm) Weight 1 lb 12 oz (0.79 kg) Shipping weight 2 lb 12 oz (1.25 kg) Single-slot Standalone Enclosure (model DE-7) Height 4 1/8 in (10.48 cm)
  • Page 121 TECHNICAL INFORMATION TECHNICAL CHARACTERISTICS (Cont.) Item Characteristic Electrical (Cont.) Communication line T1 digital carrier (non-loaded, staggered-twist ABAM, PIC, or pulp-insulated exchange-type cable, 19 to 26 gauge) Line impedance 100Ω Network physical interface RJ48C modular jack Network transmitter Pulse amplitude May vary over a cycle of 60 Hz current. Without surge protection 2.70 to 3.30 V at 60˚F With surge protection...
  • Page 122 Remote Test with Self-Test, DS1 Self-Test, DS1 Test Loop, DS0 Circuit Delay Measurement Test, DS0 Remote Test, DS0 Remote Test with Self-Test, DS0 Self-Test CSU Compatibility WECO 551 T1 compatibility Line code AMI with no bipolar violations, and B8ZS Consecutive zeros...

  • Page 124: Appendix B - Glossary

    APPENDIX B GLOSSARY Accunet Data-oriented digital services from AT&T Communications, including Accunet T1.5, terrestrial wide-band at 1.544 Mbps (formerly called T1); Accunet Reserved T1.5, satellite-based channels at 1.544 Mbps primarily for video teleconferencing applications; Accunet Packet Services, packet-switching services; Accunet Data- phone digital service (DDS), private-line digital circuits at 2.4, 4.8, 9.6, and 56 kbps.
  • Page 125 GLOSSARY Bit Error Rate (BER) The percentage of received bits that are in error, relative to a specific amount of bits received; usually expressed as a number referenced to a power of 10; e.g., 1 in 10 5 . Blue Alarm Signal See Alarm Indication Signal.
  • Page 126 DataCommonality General DataComm's term to describe a unique packaging technique that pro- vides (1) high density modular packaging, (2) a broad array of versatile data sets and accessories, (3) system flexibility and ease of expansion, (4) low power con-...
  • Page 127 GLOSSARY Data Communications Equipment. A term usually meant to refer to the modem portion of a data communications network. Also, data circuit-terminating equip- ment. In the case of an EIA/TIA-232-E (RS-232-C) connection, the modem is the DCE; in a CCITT X.25 connection, the network access and packet-switching node is the DCE.
  • Page 128 GLOSSARY Excessive Bipolar Violation Condition An excessive bipolar violation condition occurs when more than 1,544 bipolar vio- lations (BPVs) occur in 1,000 consecutive seconds. The condition clears when no BPVs occur for 85 consecutive seconds. A BPV is the occurrence of two or more consecutive bits in the DS1 signal that do not alternate between signal levels as required by the network for the Alternate Mark Inversion (AMI) line code.
  • Page 129 In response to receiving an LOS from one side, the CSU re- turns a Yellow alarm, and transmits an AIS to the other side. Master CSU A DataComm 551 option that allows configuration of the CSU through the Supervi- sory terminal. M o d e m Modulator/demodulator;...
  • Page 130 GLOSSARY Node A point where one or more functional units interconnect transmission lines (ISO); a physical device that allows for the transmission of data within a network; an end-point of a link or a junction common to two or more links in a network (IBM SNA);...
  • Page 131 One-way data transmission, with no capability for changing direction. Slave CSU A DataComm 551 option that prevents configuration of the CSU through the Supervisory terminal. A slave CSU displays a warning message when the user at- tempts to configure it or start a Self-Test or a loopback, although it does not prevent these tests.
  • Page 132 GLOSSARY Supervisory Port An interface on the DataComm 551 to which the Supervisory terminal is con- nected. Supervisory Terminal A terminal that provides software-control configuration, diagnostics, maintenance for one or all DataComm 551s in a network. Switched Network Communications link for which the physical path, established by dialing, may vary with each use (e.g., a dial-up telephone circuit).

  • Page 134: Index

    INDEX Alarm Counts screen, 3-14 DS0 Diagnostics Screen, 3-28 Alternate Mark Inversion (AMI), see Line code DS0 Remote Test, 1-3, 3-29, 4-2, 4-19, 4-21 Applications, 1-3 DS0 Remote Test with Self-Test, 1-3, 3-29, 4-2, 4-19, 4-22 dial-up modem, 1-6, 2-9, 2-23, 2-24, 3-1, 3-6 DS0 Self-Test, 4-2, 4-23 direct connection, Supervisory terminal, 2-23 DS1 Diagnostics, 4-1, 4-7...
  • Page 135 INDEX Installation, 2-1 DS1 Self Test screen, 3-21 DataComm Enclosure, 2-3 electrical connection, 2-23 DataComm FourPak Enclosure, 2-3 interface characteristics, 2-23 DataComm Modem Shelf, 2-3 keyboard usage, 3-10 GDC TriPak Enclosure, 2-3 log-on screen, 3-8 procedures, 2-1 Loopbacks screen, 3-25 Universal System Shelf, 2-5 Main Menu, 3-9 Line Build-Out, 1-1, 2-14, 2-15, 3-35, 4-5, 4-10, 4-11...
  • Page 136 INDEX PATENT NOTICE is a patented method and apparatus of General DataComm, Inc. (U.S. Patent 3,655,915). ANALOOP ® is a patented method and apparatus of General DataComm, Inc. (U.S. Patent 3,769,454). DATALOOP ® TRADEMARK NOTICE ® and the following are Trademarks of General DataComm, Inc.

Table of Contents