Austin Nelson Posted October 9, 2019 Report Share Posted October 9, 2019 Hello, I am trying to communicate to an Automation Direct VFD through Modbus. Since this is just a small proof of concept project I have taken the Modbus example code and modified it to attempt the read the output frequency of the drive. Unfortunately I am not getting any communication between the VFD and HMI and am unsure why. No one in our office has much experience with Modbus, and none with Unitronics Modbus programming so I am hoping someone on here can help. I've made a cable using a RJ4C6P connector on each end of the cable. I made the cable similar to the one described in the GS2 manual as seen below, but pin 2 to pin 2, pin 3 to pin 3, pin 4 to pin 4, and pin 5 left blank. Using RS232, switches are in default on HMI and VFD switches set to RS232. I have changed the following parameters: P9.01 to 1 - 9600 baud rate P9.02 to 5 - Modbus RTU Mode, 8 Data bits, Odd Parity, 1 Stop bit I am hoping someone has some ideas to get me going in the right direction, any help is greatly appreciated. GS2 Manual if needed: https://cdn.automationdirect.com/static/manuals/gs2m/gs2m.pdf MODBUS TEST.vlp Quote Link to comment Share on other sites More sharing options...
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