I need help to control a Golander pump through MODBUS protocol

[qsua]

Hi, I am new to LabVIEW. And I am trying to control our Golander pump through LabVIEW. I wrote the following program in LabVIEW but the pump doesn't do anything. Can someone help me check the code?

[LVNinja]

Hi qsua

Here are a few things you can check: 

I assume you're communicating with RS-485, 

- check the serial port configuration 

- try to read data first from the Modbus device to test that the communication is going through from the input registers (for ex 1023 product information)

- don't use loop while, just use one single strip : serial configuration, write, wait a few milisseconds( you need to try a number you need to wait for hthe instrument to respond) then read it. 

- then try to write data into the register you need. Sometimes to write one command you may need to send multiple messages to the instrument obey you. 

RKo

[qsua]

Hi Rko,

Thank you for your reply. I am communicating with RS-485.

- By test through the input registers do you mean the following? I have attached figures and the vi for you to check.

- I have removed the while loop but still did not let the pump run.

- I am not sure if the processes I am using is the right ones to use.