MODEL DSU Kbps Rack Mount CSU/DSU OPERATOR S MANUAL. 280 I-80 West Exit 1 PO Box 1330 Verdi NV 89439

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MODEL DSU-56 56 Kbps Rack Mount CSU/DSU OPERATOR S MANUAL 280 I-80 West Exit 1 PO

1 MODEL DSU Kbps Rack Mount CSU/DSU OPERATOR S MANUAL 280 I-80 West Exit 1 PO Box 1330 Verdi NV TEL: FAX:

2 DSU-56 Rack Mount TABLE OF CONTENTS SECTION 1 - DESCRIPTION SECTION 2 - SPECIFICATIONS SECTION 3 - INSTALLATION SECTION 4 - CONTROLS AND INDICATORS SECTION 5 - INTERFACE SIGNALS SECTION 6 - TROUBLESHOOTING Communications LLC 280 I-80 West Verdi, NV Phone: (775) December 22, 2005 Fax: (775) Rev. A Page 2

3 1. DESCRIPTION The DSU-56 is designed for 56,000 bps synchronous, or up to 9600 bps asynchronous, operation over 4-wire point-topoint or multi-point digital leased lines. The DSU-56 can also be used as a point-to-point line driver over customer owned wire for links up to 5 miles. For the typical point-to-point application, the DSU-56 can be attached to the phone line, plugged in and be in operation in minutes. The DSU-56 is very simple to set up. It has just three setup switches. One selects line driver clock for use on customer owned cable, the second forces RTS on or allows terminal control of RTS. The third switch either enables or disables a ten second anti-streaming timer. When antistreaming is enabled, the DSU-56 data output will go to an idle (off) condition if RTS stays on for at least five seconds. This feature prevents a remote terminal device, that holds RTS on, from disrupting a multidrop line. Special features of the DSU-56 include the following: Easy setup Telephone company digital line use or local line driver Anti-streaming timer Page 3

4 2. SPECIFICATIONS 2.1 Data Signaling Rates and Modulation Digital line rate of 56,000 bps Bi-polar non-return-to-zero modulation 135 ohm ± 10% transmit impedance Transmit 135 ohm load, 56 kbps, 1.4v peak 135 ohm ± 10% receive impedance Receive level sensitivity, -49 db Automatic equalization 2.2 Operating Mode Full duplex Constant or switched carrier Point-to-point or multi-point 2.3 DTE Timing Synchronous rate of 56,000 bps Asynchronous rates up to 9600 bps 2.4 Transmission Line 4 wire leased line, telephone company digital line (DDS) 4 wire in-house, 2 twisted pair, for line driver 2.5 Loopbacks Telco initiated current reversal (CSU) or non-latching DSU loopback. Local loopback switch. 2.6 Connectors Telco: RJ-48S RS-232D: DE-9 female Page 4

5 2.7 Physical/Electrical 6.25H x 9.375D 12 VDC Less than 2 watts. 2.8 Environmental Operation: -40 to +75 C, 10 to 85% relative humidity Storage: -40 to +85 C, 10 to 85% relative humidity Page 5

6 3. INSTALLATION 3.1 Unpacking The following is included with each DSU-56: DSU-56 manual 3.2 Setup The DSU-56 will typically work in point-to-point applications right out of the box. The default configuration covers 90% of typical applications. The defaults are as follows: Slave clock (phone company timing) RTS and CTS forced ON Anti-streaming disabled For multi-point applications, set the remote DSU-56s for RTS Control FROM INTERFACE (switch position 2 UP) and Anti-streaming ENABLED (switch position 3 UP). For in-house line driver applications, set the host DSU-56 for MASTER timing (switch position 1 UP). The remote unit should remain set for Slave clock. DIP switch (S1) is located on the rear of the unit. See paragraph 4.1 for more information. Page 6

7 4. CONTROLS AND INDICATORS 4.1 Switches DIP switches are located at the rear of the DSU-56 near the bottom of the circuit board. The switch functions are shown in the following table: UP DOWN Switch 1 Switch 2 Switch 3 Master RTS From Anti-streaming Clock Interface Enabled Slave RTS Forced On Anti-streaming Clock Disabled A pushbutton switch on the front of the circuit board is used for local loopback. 4.2 Indicators RCV Flashes when data is being received. CAR Normally ON, off when no signal (carrier) is being received from the far end. RTS ON if forced on or high from the interface. OFF if not forced on and low from the interface. XMT Flashes when data is being sent. CTS Always follows RTS. LB ON when local loopback is active. RCV CAR RTS XMT CTS LB Loopback Switch DSU-56 Loopback Switch and Indicators Page 7

8 5. INTERFACE SIGNALS 5.1 Card Edge Connector Pin Signal Name In/Out A,B Ground C,D +12 VDC IN K Data Carrier Detect OUT L Request to Send IN M Transmit Data IN N Clear to Send OUT P Receive Data OUT X Transmit Tip OUT Y Transmit Ring OUT 2 Receive Tip IN 3 Receive Ring IN 5.2 TELCO Jack (RJ-48S / P4) Pin Signal 1 Transmit Data 2 Transmit Data 7 Receive Data 8 Receive Data 5.3 RS-232D / V.24 Interface (DE-9S / P3) Pin Signal Name In/Out 1 Data Carrier Detect OUT 2 Receive Data OUT 3 Transmit Data IN 4 Receive bit clock OUT 5 Signal Ground DSR +V OUT 7 Request to Send IN 8 Clear to Send OUT 9 Transmit bit clock OUT 5.4 External Power (P5) Center: +12VDC Body : Ground Page 8

9 6. TROUBLESHOOTING 6.1 Field Troubleshooting Flowchart DSU and Phone Line Troubleshooting Chart START Local DCD On? Remote DCD On? Reset Both DSUs Both DCDs On? Reset Local DSU Local DCD On? Call TELCO TELCO Says OK Remote DCD On? Reset Remote DSU Remote DCD On? Both DCDs On? Replace DSU With DCD ON Is Link Up? Replace Both DSUs DONE Page 9

10 6.2 Bench Test Procedure +12VDC Power TELCO RS-232D/V.24 DIP P5 P4 P3 SW1 DSU-56 Rear View In the following procedure, test steps are against the left margin and normal indications (results) are indented as bullets. VOLTAGE LEVEL TEST Connect a 12VDC power source to P5. The center pin is positive. Measure voltage at the center pin of voltage regulator (U4). Voltage reads to volts WARNING! If voltage is not within specified limits, turn off power immediately. CLOCK OUTPUT TEST Using a frequency counter measure the transmit and receive clock frequency at P3-4 and P3-9. Both pins should read to KHz The following cable is required to connect the BT-1 tester to the DSU-56. DE-9P DB-25S Page 10

11 POINT-to-POINT TEST TE If a DDS telephone line is not available, connect the DSUs using a crossover cable and put DIP switch 1 UP on one unit only. Connect equipment as shown below. DDS Telco Line BT-1 DSU-56 DSU-56 BT-1 RTS (DS3), CTS (DS5) and CAR (DS2) are ON. Set both BERTs for EXTRN Timing. Press RUN on BERTs. BERTs run error free on both Tx and Rx. XMT (DS4) and RCV (DS1) are ON. Press STOP on BERTs. ASYNCHROUS TEST Set both BERTs for 9600 bps Press RUN on both BERTs. Data runs error free. Press STOP on BERTs. ANTI-STREAMING TEST Set DIP switch 3 UP on one DSU-56 at a time. RTS (DS3) and CTS (DS5) go off in approximately 5 seconds. Set DIP switch 3 DOWN on both units. Page 11

12 POLLING TEST Set one BERT as a Master (host) SET PARM Timing: EXTRN RTS Holdover: 0 ms TXD Holdoff: 5ms SET TEST Poll: MST-01 Sync Char: ASy Set the other BERT as a Slave (remote) SET PARM Timing: EXTRN RTS Holdover: 0 ms TXD Holdoff 5ms SET TEST Poll: SLV=01 MSG: LF Sync Char: ASy On the DSU-56 connected to the Slave BERT, set DIP switches 2 and 3 UP. RTS (DS3) and CTS (DS5) go OFF. CAR (DS2) goes off on the other DSU-56. Press RUN on the Slave BERT. Press RUN on the Master BERT. On the Master DSU-56, CAR (DS2) flashes. On the Slave DSU-56, RTS (DS3) and CTS (DS5) flash. On both BERTs, RTRY=00 STOP BERTs. Reverse the master and slave DSU-56s and repeat the polling test. Set both BERTs for 9600 bps and repeat the polling test. RESET DEFAULTS Put DIP switches 1, 2 and 3 DOWN on both units. END OF TEST Page 12

OPERATOR S MANUAL MODEL DSU-56SA. 56 Kbps Stand Alone CSU/DSU

OPERATOR S MANUAL MODEL DSU-56SA. 56 Kbps Stand Alone CSU/DSU MODEL DSU-56SA 56 Kbps Stand Alone CSU/DSU OPERATOR S MANUAL 280 I-80 West Exit 1 PO Box 1330 Verdi NV 89439 Tel: 775-345-8000 Fax: 775-345-8010 E-mail: support @sgdi.net DSU-56SA TABLE OF CONTENTS SECTION