P300H P300 Series Modem Installation and Operating Handbook Page 181
1 FOR 1 INTERFACEConnector type : 9 Pin `D' male
1:1 CONNECTOR
1 Ground
2 Line in
3 Line out
6Fail in
7 Fail out
4 Serial in (unused)
8 Serial out (unused)
5 Not used
9 Not used
Serial In/Out
This is an uncommitted and currently unused RS232 serial port.
Line In/Out & Fail In/Out
A suitable four way lead (4 + Screen) 1:1 redundancy lead is as follows:
Unit 1 Unit 2
Pin 1 ...Screen... Pin 1 (circuit ground)
Pin 2 ................. Pin 3 (On- Line signal 2-1)
Pin 3 ................. Pin 2 (On- Line signal 1-2)
Pin 6 ................. Pin 7 (Fail signal 2-1)
Pin 7 ................. Pin 6 (Fail signal 1-2)
Keep this lead as short as practical, and ensure it is screened t o prevent spurious changeovers by noise
induced in these high impedance signal leads.
Refer to the earlier section on 1 FOR 1 switching for details of 1 FOR 1 operation.
A standard 1 FOR 1 l ead is available from Paradise Datacom, part number P1391. The lead is 10cm
long, and is designed for use when two Modem are mounted vertically adjacent to each other in the rack.