11-27-2017 11:09 AM
Hello,
I have a test system which cycles pressures via two solenoid valves and a pressure controller. The system is currently controlled by DirectLogic 06 PLC. I would like to know if its possible to use labview to communicate with DirectLogic 06 PLC via OPC or Modbus so that I can control solenoid valves and pressure controller in VI ? I hope to expand system complexity and add User interface using Labview.
Regards
Fliu
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11-27-2017 11:13 AM
Modbus is easy using the NI-supplied Modbus libraries, I've done it with various DirectLogic PLCs.
11-27-2017 12:25 PM - edited 11-27-2017 12:26 PM
Awesome ! The Directlogic 06 PLC is currently programmed using DirectSOFT in Ladder Logic. Once in run mode, PLC will execute those code. How will I be able to get rid of that program so I can program using labview via modbus ?
11-27-2017 02:19 PM - edited 11-27-2017 02:21 PM
If you want to completely eliminate the PLC code and essentially just use the PLC's inputs and outputs as field I/O, you can load it with an empty program (don't forget the END or it won't compile) and use Modbus to read and write input and output bits and registers. However, you might want to keep some basic code in the PLC for doing low-level tasks, and just set things like setpoints or timer presets from the computer via Modbus. You can also use the DL06's stages like subroutines which can be activated by setting the stage bits.