Digital Modem Installation Guide

84 Appendix

CTA 500

On Line Guide P0873832 Issue 05

DB-25 and DB-9 signal summary

The following tables show which DB-25 and DB-9 pins are used by

the CTA 500dm and what the signals are used for by the

CTA 500dm.

DB-25 connection

DB-25

RS-232

function

CTA 500

function

1 Shield Shield

2 Transmitted Data TD

3 Received Data RD

4 Request to Send/Ready for Receiving RTS

5 Clear to Send CTS

6 DCE Ready DSR

7 Signal Common GND

8 Received Line Signal Detector DCD

12 Secondary Received Line Signal/Detector/

Data Signal Rate Selector (DCE Source)

–

13 Secondary Clear to Send –

14 Secondary Transmitted Data –

16 Secondary Received Data –

18 Local Loopback –

19 Secondary Request to Send –

20 DTE Ready DTR

22 Ring Indicator RI

23 Data Signal Rate Selector (DCE/DTE Source) –

24 Transmitter Signal Element Timing (DTE Source) no

25 Test Mode no