Brooks MFC SLA5850S Incorrect Byte count in reply error

[rv_labView]

Hello,

I am trying to communicate with Brooks MFC SLA5850S via PXIe-8341/16 using LV 2019. I am using their DLLs found online and am encountering the error "Incorrect byte count in reply". Has anyone else encountered this error before? Upon checking the command signal via a scope, we can see the command going from the NI unit to the MFC. That looks good signal wise. The response from the valve, however, doesn’t span the full 0V to 3.3V and 3.3V to 0V differential ranges, more like 0V to 1.2V and 3.3V to 1.8V ish (from a quick measure on the scope). Could this be a flow control issue (effectively the NI unit’s Transmitter not switching off when the valve is responding if I understood correctly)? Any help will be greatly appreciated.

The Brooks DLLs can be found at https://www.brooksinstrument.com/en/products/accessories-software/product-software/brooks-labview-dl...

[NPowl]

Hey rv,

I saw you created a Service Request - we can have a discussion there and I can post the outcome here 🙂

Thanks,

Nick

[NPowl]

Hey all,

Just to complete the loop on this - rv discovered the port mode has to be match between Device Manager and LabVIEW and any changes must be mirrored in both. This is primarily useful if you may not have admin rights on your PC.

Cheers,

Nick