Nortel Networks DCT1900 manual Sync Input Cable Delay Measurement, External Sync Cable TSR 951

Technical Product Manual - DCT1900

Installation Instructions, Synchronization Distribution Board (SDB) – REX-BRD0006 or ROANB 101 38

External Sync Cable (TSR 951 284)

Cable length	:	20 ft.
Wires	: 6 conductor shielded flat cable
Working Voltage	:	300V
Connector - System/Sync Port	: 6 pin shielded RJ 12 connector
Connector - Modem	: 6 pin shielded RJ 12 connector

SYNC OUT

1

2

3

4

5

6

A

B

GND(shield)

1

2

3SYNC

4IN

5

6

Figure 18–3 Wiring Diagram External Sync Cable

18.4Sync Input Cable Delay Measurement

The external sync input cable delay must be measured in order to input the system synchronization delay into the system at initialization. The system synchronization delay compensates for the delay introduced by the cable. The external sync input cable delay is measured as follows:

1.Make sure that the other end of the external sync input cable is not connected.

2.Connect a TDR to the terminals 3 and 4 on this end.

3.Measure the cable delay. The resulting value must have an accuracy of 50ns (corresponding to 16ft. – 33ft.).

4.Note the cable delay value.

Install-DCT1900/R8/mw	18-3
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