Modbus serial Slave in RTU (Remote Terminal Unit) mode for an FM4E and EN drive controller

[PIC]

I am trying to communicate with a FM4E and EN drive controller using a Modbus serial protocol. The Modbus serial protocol must be a Modbus Slave in RTU (Remote Terminal Unit) mode. I have downloaded and tried NIModbus.llb with no success. Can anyone assist?

[mikeporter]

Are you getting specific error? What is happening?

Mike...

[PIC]

Mike,

I am following National Instruments Application Note 211 for configuring LabVIEW as a Modbus Slave Device. The errors received are Error at Invoke Node and VI is not compatible for this operation.

PIC

[unclebump]

I think Labview should act as the modbus master in this case. When you connect an operator interface to the FM4, the HMI screen acts as a modbus master to read data from the FM4 slave. I think the FM4 will act as a modbus slave device in this case.

[PIC]

Using LabVIEW's Modbus library, NIModbus.llb,  LabVIEW has been configured as a Modbus Master Device. I am broadcasting address 0 and attempting to communicate to RTU address. The Master timeouts-error at address 1 and no response using address 0.

Any suggestions?

[unclebump]

Show us some code. How do you have the FM4 configured for Modbus addresses?? Here is an llb file that I made to query modbus info from the serial port.