Modbus%2C Despatch oven and Protocol 3

[ncm]

I have a Despatch oven that is using Protocol 3 which communicates using Modbus over RS485.  I am using the Modbus library that I found though the forum and am still having troubles communicating with the controller.  I am using a USB RS485 converter and my converter is set to half duplex 2 wire without echo.  I am able to transmit but not receive a message back from the oven.  Does anyone have any experience or any insight on how to work LabVIEW with this equipment? 

[a_clucker]

Hi ncm,

NI officially supports the modbus libraries that ship with both the DSC Module and the Real-Time Module. The free download is unsupported, but there is a forum that might assist you. Please post your question to the Industrial Communications forum page.

Thanks!

[Dennis_Knutson]

How do you know that the transmit is correct? You won't get an error even with the instrument disconnected.

[ncm · Accepted solution]

Hey everyone,

I was able to trouble shoot the setup and found that the oven came to us wired backwards, the situation is remedied and the Modbus is communicating nicely.  Thanks for the responses!