Westermo TD-22 - Manual (Page 5)

25 Pin Screw Direction Name Description
D-sub Terminal DCE-DTE
1 - - - PE Protective earth
2 8 TXD Transmit data
3 7 RXD Receive data
4 6 RTS Request to send
5 5 CTS Clear to send
6 2 DSR Modem ready
7 1 - - - SG Signal ground
8 4 DCD Data carrier detect
9 Continuous high
10 Continuous low
12 DRS Speed indication (1200/2400)
15 TXC Synchronous TXD clock from modem
17 RXC Synchronous RXD clock from modem
20 3 DTR Data terminal ready
21 RDL Request of remote digital loopback
22 9 RI Ring indicator
23 DRS Data speed select (1200/2400)
24 EXC External synchronous clock
25 TI Test indication signal
6 6177-2203
RS-232 Connections
Pin outs for the 25-pole D-sub and 9-pole screw terminal:
The other pins in the 25-pole D-sub should be left unconnected.
Line connection
The telephone line is connected to the 6-pole RJ-12
connector or to the 4-pole screw block in the bottom
left side.
When using the screw-block a strap plug supplied must
be placed in the RJ-12 connector. If this is not done the
outgoing signal will not be connected to the screw-
block.
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6
1 2 3 4
2-wire lines are connected to the two middle pins
(3 & 4) in the RJ-12 plug or the TX screws
(1 & 2).
In the UK modems the RJ-12 connection is on pin
2 & 5.
4-wire lines are connected to the screw terminal,
transmitter to TX (1 & 2) and receiver to RX (3 & 4).