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MT56DSU-R  Owner's  Manual

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3.1 Introduction

This  chapter  provides  information  on  the  operating  functions  of  the

MT56DSU-R.  During  normal  operation  the  MT56DSU-R  requires  no

operator  intervention.

Many  of  the  optional  features  of  the  MT56DSU-R  are  selected  by

setting  a  switch.  Please  refer  to  changing  the  default  DIP  switch

settings  in  Installation  (Chapter  2)  to  change  your  particular

environment.

3.2 Options

The  switchable  features  of  the  MT56DSU-R  are:

•

Data  Rate

• Clocking

•

Async/Sync

• RTS  Forced  On

•

Anti-Streaming

• DSR  Forced  On

•

Elastic  Store

• Async  Word  Length

•

System  Status

• Normal/Diagnostics

•

Circuit Assurance

The  MT56DSU-R  has  a  pre-configured  (default)  setting  for  each  of

these  options  when  shipped  from  the  factory.  Chapter  2  of  this

manual  covers  the  changing  of  these  option  DIP  switches.  Chapter  4

covers  the  Normal/Diagnostic  switch  function.  The  following  sections

describe  the  option  in  terms  of  the  operation  of  the  MT56DSU-R  in  a

DDS  or  other  4-wire  network.

3.2.1

Data  Rate

This  option  allows  selection  of  the  MT56DSU-R’s  data  transmission

rate.  The  data  rate  selected  here  must  match  the  DDS  or  other  4-

wire  network  line  rate  that  you  subscribed  for  with  your  telco.

The  default  for  this  function  is  a  data  rate  of  56K  bps.  (Refer  to

Chapter  2  for  option  switch  selection.)

3.2.2

Async/Sync

This  option  allows  selection  of  the  MT56DSU-R’s  type  of  data

transmission  used.  The  transmission  type  selected  here  must  match

the  DTE.  The  default  is  “sync”  (synchronous  data  transmission).

82023101.p65

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Summary of Contents for MT56DSU-R

Page 1: ...MultiDSU56K TM Rack Mount Multi Rate DSU Model MT56DSU R Owner s Manual 82023101 p65 2 12 01 2 52 PM 1...

Page 2: ...revise this publication and to make changes from time to time in the content hereof without obligation of Multi Tech Systems Inc to notify any person or organization of such revisions or changes Recor...

Page 3: ...t DIP Switch and Jumper Settings 16 2 2 1 12 Position DIP Switch 1 12 17 2 2 2 4 Position DIP Switch 13 16 17 2 2 3 RS232 V 35 Shunt 17 2 3 Changing the Default DIP Switch Settings 18 2 4 Installation...

Page 4: ...34 4 2 8 NS Indicator 34 4 2 9 TM Indicator 34 4 2 10 OOS Indicator 34 4 3 Diagnostic Tests 35 4 3 1 Local Loopback Test 35 4 3 2 Digital Loopback Test 36 4 3 3 Digital Loopback With Test Pattern Test...

Page 5: ...MultiDSU56K TM Chapter 1 Introduction and Description 82023101 p65 2 12 01 2 52 PM 5...

Page 6: ...manual is provided as described below Chapter 1 Introduction and Description contains an introduction to the MT56DSU R product and its features and functions Chapter 2 Hardware Installation provides...

Page 7: ...such the MT56DSU R provides all of the functions required on the customer side of the network The MT56DSU R provides user selection of synchronous data communications at rates of 2400 4800 9600 19200...

Page 8: ...pplications The MT56DSU R contains the functions of a Data Service Unit DSU and a Channel Service Unit CSU in a single package 1 4 1 DSU Functions The DSU encodes data as pulses on the communications...

Page 9: ...ect connection to the DATAPHONE Digital Data Service DDS or compatible network selectable sync speeds of 2400 4800 9600 19200 and 56000 bps selectable async speeds of 2400 4800 9600 and 19200 bps poin...

Page 10: ...he line as determined by the total REN s contact the telephone company to determine the maximum REN for the calling area 4 If this equipment causes harm to the telephone network the telephone company...

Page 11: ...rovided by the telephone company Contact the state public utility commission public service commission or corporation commission for information Manufacture Multi Tech Systems Inc Model number MT56DSU...

Page 12: ...ted Compatibility AT T Pubs 62310 and 41450 FIC Codes 04DU5 24 2 4 Kbps digital interface 04DU5 48 4 8 Kbps digital interface 04DU5 96 9 6 Kbps digital interface 04DU5 19 19 2 Kbps digital interface 0...

Page 13: ...oduction and Description 13 Input Impedance 135 ohms Delay Times in msecs RTS CTS DCD on DCD off 2400 8 1 7 5 7 0 4800 4 3 2 6 3 5 9600 2 2 1 6 1 5 19200 1 0 8 0 7 56000 0 4 0 3 0 2 82023101 p65 2 12...

Page 14: ...MT56DSU R Owner s Manual 14 82023101 p65 2 12 01 2 52 PM 14...

Page 15: ...MultiDSU56K TM Chapter 2 Hardware Installation 82023101 p65 2 12 01 2 52 PM 15...

Page 16: ...as shown in Figure 2 1 They are located behind the LEDs on the front of the board Each individual switch is numbered and can be in either the up OPEN or down CLOSED position The MT56DSU R is shipped...

Page 17: ...Word Length Elastic Store and Anti Streaming options The defaults are 10 Bit Async Word Length Elastic Store disabled and Anti Streaming disabled If changes to these settings are required refer to sec...

Page 18: ...e illustrated in Figure 2 1 The factory default settings are indicated by an in the Table 2 1 Table 2 1 MT56DSU R Switch Settings Switch Description Data Rate in bps 2400 4800 9600 19 2K 56K 1 Down Do...

Page 19: ...rn enabled Link Status Options 11 Up Circuit Assurance disabled Down Circuit Assurance enabled 12 Up System Status disabled Down System Status enabled Async Word Length 9 Bit 10 Bit 11 Bit 13 Up Down...

Page 20: ...RS 232 position If the MT56DSU R is being connected to a V 35 interface place the 16 pin shunt in the V 35 position 3 Determine which slot the MT56DSU R board is going to be placed in the rack Apply...

Page 21: ...is manual for V 35 Interface Adapter cable information Refer to the Rack Mounted Modems Owner s manual for cable connections on the rack 8 To connect the phone line to the MT56DSU R using the phone ca...

Page 22: ...MT56DSU R Owner s Manual 22 82023101 p65 2 12 01 2 52 PM 22...

Page 23: ...MultiDSU56K TM Chapter 3 Operation 82023101 p65 2 12 01 2 52 PM 23...

Page 24: ...tting for each of these options when shipped from the factory Chapter 2 of this manual covers the changing of these option DIP switches Chapter 4 covers the Normal Diagnostic switch function The follo...

Page 25: ...or changing the default DIP switch settings 3 2 4 Elastic Store This function allows the MT56DSU R to compensate for small timing phase drifts that occur in applications using analog modems for off ne...

Page 26: ...reting momentary line interruptions as a communications channel failure Refer to Chapter 2 for changing the default DIP switch settings 3 2 6 Circuit Assurance This option when enabled causes the MT56...

Page 27: ...bled Refer to Chapter 2 for changing the default DIP switch settings 3 2 8 RTS Forced On With this option enabled the MT56DSU R provides a continuous CTS signal disregarding the state of the RTS signa...

Page 28: ...ed On Refer to Chapter 2 for changing the default DIP switch settings 3 2 10 Async Word Length This option allows you to select the word length to be used by the MT56DSU R for asynchronous data transm...

Page 29: ...nforms to the signal power requirements of Bellcore Pub 41028 data sets used on LADC when used at subrate speeds less than or equal to 19200 bps The MT56DSU R does not meet this requirement at the 56K...

Page 30: ...t extension one MT56DSU R may be set for External Timing and the other set for DDS Timing however in this application the clock timing being supplied must be accurate to 0 008 of the enabled data tran...

Page 31: ...MultiDSU56K TM Chapter 4 Troubleshooting 82023101 p65 2 12 01 2 52 PM 31...

Page 32: ...ns ten LEDs each with a two or three letter overlay describing its meaning During normal operation the LEDs light flash or continuously lit to indicate the operating status During test mode the LEDs l...

Page 33: ...off on the remote DSU the remote sends an idle code to the local DSU 4 2 4 56K Indicator The 56K LED lights when the Data Rate selection is set at 56000 bps This indicator will be off for all other d...

Page 34: ...TM Indicator The TM Test Mode LED lights when one of the Test switches is set to the down Test enabled position When the TM LED is lit normal operation network transmit receive cannot occur Refer to...

Page 35: ...eck the remote far end transmitting equipment If the remote equipment is transmitting properly contact your telephone company If the telco is required to perform remote tests the channel will be tempo...

Page 36: ...56DSU R Use the following steps to perform the Digital Loopback Test 1 Set DIP switch 9 on the remote MT56DSU R to the down position 2 The Test TM LED lights and if you send data from the local DTE it...

Page 37: ...the MT56DSU R sends and detects a pre defined 15 bit pseudo random test pattern When an error is detected by the MT56DSU R the NS No Signal LED flashs 1 Set DIP switch 9 on the remote MT56DSU R to the...

Page 38: ...ndom test pattern When an error is detected by the MT56DSU R the NS No Signal LED flashs To enable the Test Pattern Test perform the following 1 Set the DIP switch 10 on both the local and remote MT56...

Page 39: ...cription 1 Obtain a DSU Loopback cable CADSURLB from Multi Tech or assemble one Refer to Appendix B for instructions on building the Loopback cable 2 Plug the Loopback cable into the DB9 connector on...

Page 40: ...ulti Tech or assemble one Refer to Appendix B for instructions on building the Back to Back cable 2 On the good DSU board set DIP switch 9 to the down position 3 Set one DSU to internal clocking and t...

Page 41: ...MultiDSU56K TM Chapter 5 Warranty Service and Tech Support 82023101 p65 2 12 01 2 52 PM 41...

Page 42: ...date of purchase or if proof of purchase is not provided two years from date of shipment MTS MAKES NO OTHER WARRANTY EXPRESSED OR IMPLIED AND ALL IMPLIED WARRANTIES OF MERCHANTABILITYAND FITNESS FOR A...

Page 43: ...itional information The phone number for the Multi Tech BBS is 1 800 392 2432 in the U S and Canada and for Worldwide calls 612 785 9875 The BBS can be accessed by any asynchronous modem operating at...

Page 44: ...MT56DSU R Owner s Manual 44 82023101 p65 2 12 01 2 52 PM 44...

Page 45: ...MultiDSU56K TM Appendixes 82023101 p65 2 12 01 2 52 PM 45...

Page 46: ...cal Area Data Set External Clocking application and Analog Off Net Extension application DDS Point To Point Application In this application the MT56DSU R provides the interface between the DDS line an...

Page 47: ...mote stations and have RTS controlled by the DTE Multi point DDS provides communication between a control station and two or more remote stations All data transmitted by the control station is sent to...

Page 48: ...a Data Set Application External Clocking Application This application is similar to theLocal Area Data Set application except for the timing option setting In the example below the DTE connector of th...

Page 49: ...used with conventional analog modems and lines to complete DDS circuits in an area where DDS is not available Site 3 in the example below or where the customer requires an extension of the DDS circui...

Page 50: ...is connector ties the MT56DSU R to the DDS Network The DB9S connector has the following pinout configuration PINIDENTIFICATION Pin Description Destination 1 Transmit Pair To Line 2 N C 3 Transmit Pair...

Page 51: ...18 17 16 15 14 Transmitter Signal Element Timing As viewed from the rear DESCRIPTION This connector ties the MT56DSU R to the DTE The DB25S connector has the following pinout configuration PINIDENTIF...

Page 52: ...uld be used when the MTDSU56 R is configured for V 35 DTE interface You can order the V 35 Interface Adapter cable CADSUR35 from Multi Tech This cable uses a 25 pin male connector at one end and a 34...

Page 53: ...C BUILDINSTRUCTIONS 1 Strip cable insulation 3 4 2 Strip wires 1 3 4 and 8 on one end of cable and 1 2 7 and 8 on other end a 1 4 3 Cut unstriped wires off 4 Solder wire 1 on one connector to 1 on the...

Page 54: ...r comparison to the original signal sent You can order this cable CADSURLB from Multi Tech or build one using the instructions below Refer to Chapter 4 for test procedures SCHEMATIC BUILDINSTRUCTIONS...

Page 55: ...can order it from Multi Tech CADSURBB or build one using the instructions below Refer to Chapter 4 for test procedures SCHEMATIC BUILDINSTRUCTIONS 1 Strip cable insulation 3 4 3 Strip wires 1and 3 on...

Page 56: ...MT56DSU R Owner s Manual 56 82023101 p65 2 12 01 2 52 PM 56...

Page 57: ...MultiDSU56K TM Glossary 82023101 p65 2 12 01 2 52 PM 57...

Page 58: ...ing parameters of a data communications line bps bits per second unit of measure for data transmission C Central Office CO the telephone company site where switching equipment is located as opposed to...

Page 59: ...See also DTE DDS Dataphone Digital Service AT Ts private line end to end digital service with data rates typically at 2400 4800 9600 19200 and 56000 bps Now an AT T Accunet family offering The DDS is...

Page 60: ...criber for a fixed fee LED Light Emitting Diode a light source that emits visible light Local loopback a type of diagnostic test where the transmitted signal is returned to the sending device after pa...

Page 61: ...multipoint DDS network that communicates with the master station via the OCU All remote stations on the DDS must operate at the same bit rate AKA outlying station RJ Registered Jack a connector for us...

Page 62: ...a diagnostic test for sending detecting and checking a pre defined pattern of bits Two wire circuit A circuit in which one channel line is used for communications in both directions Contrast four wir...

Page 63: ...Glossary 63 82023101 p65 2 12 01 2 52 PM 63...

Page 64: ...82023101 82023101 p65 2 12 01 2 52 PM 64...

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