PA 7400
Technical description Chapter 8
40
•
Invert the open-circuit potential
of the receive lines RxA+(RxB+) and RxA-
(RxB-).
Set
the jumpers as follows:
J19(14) in pos. A
J20(15) in pos. B
Fig. 8-10: Inserting a terminator and inverting the open-circuit potential
RS 485 cabling - serial port 1
Fig. 8-11: RS 485 cabling for serial port 1
•
If the communication software supports the control of the modem control signals,
è
connect
the modem control signals as follows to the connector.
RTSA
→
CTSA
DTRA
→
DSRA
→
DCDA
→
RIA
RS 485 cabling - serial port 2
The modem control signals are connected on the board as follows:
RTSB
→
CTSB
DTRB
→
DSRB
→
DCDB
→
RIB