Westermo TD-22 - Manual (Page 6)

7 6177-2203
Typical TD-22 line connections
4-position
screw-terminal
Handshaking
Leased line 2-wire
Telephone
exchange Telephone
exchange
Dial up line 2-wire
Telephone modem
4-position
screw-terminal
4-position
screw-terminal
RJ-12 connector
Leased line 4-wire
Telephone
exchange Telephone
exchange
Dial up line 2-wire
Telephone modem
1 2 3 4 5 6 7 8 9
The TD-22 is delivered with a factory setting for ”hardware hand-
shake” with RTS-CTS which means that if only TX, RX and GND
are connected no data will be sent on the receiving modem’s RS-232
connection unless RTS is high. The problem can be solved by placing
a jumper between RTS (screw terminal no 6) and for example DSR
(screw terminal no 2) or by disabling the handshake with the command
AT&K0.
3
4