User`s manual

Western Reserve Controls 1782-JDM User’s Manual
PUB 24.0
14
3.3 RS232/RS485 Connector
Your Modbus device(s) are connected to the JDM via 3-wire communications cable. See your Modbus
device User Manual for details on the specific connection.
Table 3-3 Serial Port Connections
Pin # RS232
Signal
RS485
Signal
Designator
1 Transmit Signal + SIG+
2 Receive Signal - SIG-
3 Ground Ground GND
3.4 Power Requirements
3.4.1 Device power
The JDM is powered directly from the DeviceNet connection 11-25 Vdc power supply. The JDM consumes
90 mA of current at 24 Vdc, or ~2 Watts, typical.
3.5 Network Configuration
DeviceNet specifications provide for a maximum network distances for the main trunk line and drop
lines, depending upon the baud rate used on the network. They are:
Table 3-4 Network Maximum Lengths
Trunk Line Length Drop Length
Maximum Distance Maximum Cumulative
Baud Rate
Meters Feet Meters Feet Meters Feet
125k baud 5OO m 164O ft 6 m 2O ft 156 m 512 ft.
25Ok baud 25O m 82O ft 6 m 2O ft 78 m 256 ft.
5OOk baud 1OO m 328 ft 6 m 2O ft 39 m 128 ft.