Campbell Scientific VSP3 Vosponder Voice Radio Interface - Manual (Page 46)

Appendix B. Cabling and Connections
B-2
Aux MPU Interface
VOSPONDER III Radio Interface Partial Schematic
(c) 2003 ISA-USA, Inc.
Receive Carrier Operated
Squelch Sense (Optional)
Receive Audio <
Transmit Audio >
Push To Talk Relay Contacts
1
2
3
4
5
6
7
8
8X8 MODULAR Plug
10K
1uF
De-energized
OP4N25
1
2
3
4
5
6
7
8
8X8 MODULAR Jack
J6
R2
3.3k 1/16w
470 1/16w
FIGURE B-4. Radio Interface Connector (Partial Schematic)