CET Electric Technology
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2.4 Input Wiring
Please consult the serial number label to ensure that the voltage and current input is less than or equal
to the meter’s input specification.
Figure 2-5 Input Connections
2.5 Communications Wiring
The following figure illustrates the RS485 communications connections on the PMC-D721MD:
Figure 2-6 Communications Connections
The PMC-D721MD provides one RS485 port and supports the Modbus RTU protocol. Up to 32 devices
can be connected on a RS485 bus. The overall length of the RS485 cable connecting all devices should
not exceed 1200m.
If the master station does not have a RS485 communications port, a RS232/RS485 or USB/RS485
converter with optically isolated output and surge protection should be used.
2.6 Digital Input Wiring
The following figure illustrates the Digital Input connections on the PMC-D721MD:
Figure 2-7 DI Connections
