Table 6-6: SDM-SIO2R functional description of sensor connections
Pin
Case text
(RS-232
Function)
RS-485
Function
Connection to
Description
1
RG
1
Sensors
Note that all of the
sensor connections are
repeated on two
connectors:
Sensor 1 and Sensor 2
RG – RS-485 ground.
Connected to G via
100 Ω 1 W resistor.
2
GND
2
GND - ground for RS-
232 communications
3
RTS
TD+
RS-232 RTS. RS-485 half
duplex non-inverting.
RS-485 full duplex
outgoing.
4
Tx
TD–
RS-232 transmit. RS-485
half duplex inverting.
RS-485 full duplex
outgoing.
5
Rx
RD+
RS-232 receive. RS-485
receiver non-inverting.
RS-485 full duplex
incoming.
6
CTS
RD–
RS-232 CTS. RS-485
receiver inverting.
RS-485 full duplex
incoming.
1
V-
AC or DC voltage source
return from power
supply
2
V+
AC or DC voltage source
from power supply
SDM-SIO2R Serial Input/Output Module with Switched Sensor Power
18
