- RAD Data Communication Fiber Optic Modem Installation and Operation Manual E1, T1

Standalone FOM-E1/T1 A-1
Appendix A
Interface Connector
Specifications
A.1 Standalone FOM-E1/T1
DB-15 Connector
Balanced E1/T1 interface terminates in DB-15 female connector, which also serves
as an alarm relay. Table A-1 describes the DB-15 pins that serve for the E1/T1
connection. Table A-2 describes the DB-15 pins that serve for the alarm relay.
Table A-1. DB-15 Pin Assignment, E1/T1 Pins
Pin Designation Function
3 Send Data (TTIP) Transmit Data, A-wire
(FOM-E1/T1 output)
11 Send Data (TRING) Transmit Data, B-wire
(FOM-E1/T1 output)
1 Receive Path (RTIP) Receive Data, A-wire
(FOM-E1/T1 input)
9 Receive Path (RRING) Receive Data, B-wire
(FOM-E1/T1 input)
Table A-2. DB-15 Pin Assignment, Alarm Relay Pins
Pin Contact Alarm Type
7, 8 Normally Closed
15, 8 Normally Open
Minor
5, 6 Normally Closed
13, 6 Normally Open
Major