PDW30 Point-to-Point Wireless Bridge Instruction Manual
10
Digital I/O Connector
All digital connections are wired to ground. The primary unit
digital I/O settings determine whether a digital connection re-
ceives power constantly or intermittently, thereby determining
whether it is an input or an output, respectively.
Note: Each connection may be set independently in the de-
vice settings as either an input or an output. In the dia-
gram to the right, D4 & D3 are digital inputs and D2 is a
digital output.
Modbus RTU Serial Communications
The PDW30 acts as a simple pass-through for Modbus communications. As such, multiple Modbus ena-
bled devices may transmit wirelessly using the PDW30 Wireless Bridge.
Figure 6. Three- and Five-Wire RS485 Modbus Connections
Figure 7. Multiple Device RS485 Modbus Connection
Notes:
1. Termination resistors are optional and values depend on the cable length and characteristic im-
pedance. Consult the cable manufacturer for recommendations.
2. Use shielded cable, twisted-pairs plus ground. Connect ground shield only at one location.
Shield
Twisted-Pair
Shield
Twisted-Pair
(PDW30 Wireless Device)
(PDW30 Wireless Device)
R
R
R
R
Shield
Twisted-Pair
(PDW30 Wireless Device)
R
R
Figure 5. Digital I/O Connections
