Interface 3300 ACM module with Quantum PLC


Thread Starter

Jean-Michel Blais

I have to interface a 3300 ACM module from Power Measurement and a Modicon Quantum PLC. I have to use Modbus protocol to initiate communication from the master (PLC) to the slave (3300 ACM) using the MSTR instruction. If anyone has an example of the configuration of the MSTR block i would appreciate. The message packet is sent from the PLC through a BM85 bridge, on to a RS-232/RS-485 converter and then to the 3300 ACM module. The response of the slave is automatic but the read message packet must be set properly to give the module adress, the start register to read, the total number of registers needed and the CRC checksum code. I also want to know if this module can work with a Quantum PLC becaus the manufacturer's document says that the module emulates a 984 controller and there are some differences in adressing between the 984 and Quantum PLC. Thanks.

Robert Willis

The Quantum PLC can support the use of the XXMIT Function Block which will allow you to use the RS232 Serial port on the Quantum as a Modbus "Master".

In your present configuration using the Modbus Plus Network the Bridge Mux will do the conversion from Modbus Plus to Modbus "Master" and then forward the message to the 3300 ACM module.

What software package are you using to program the Quantum? (Modsoft, ProWorX or Concept).

Robert Willis
Square D Company
Houston, Texas
If you use bm85 to access the 3300,just set the five-byte route path to <bm85 mb+Addr>.<bm85 mb port No>.<3300 slave Addr.> and set the bm85's port type to 'Network', and set a slave address to 3300.