Utility MODBUS RTU Receive Message.vi Error

[alright_meow]

I am currently using the watlow F4 drivers that i got from NI. One of the private files: Utility MODBUS RTU Receive Message.vi is giving me errors everytime i run anything. I have narrowed it down to the property node giving me this specific error attached below. If i take this property node out, then it will time out on the visa read. I have tried to adjust time outs, and bit sizes as seen in other forums, and still wont help.

I using the ICS Electronics(model 4899A) GPIB to MODBUS interface.

[RavensFan]

DON'T ATTACH BITMAP FILES TO YOUR MESSAGES AND GET AROUND THE BAN ON BITMAPS BY CHANGING THE EXTENSION TO .JPG.

Either attach actual jpeg files, or better yet, save the images as .png and attach those.

The error you get is about a specified attribute is not supported by the device.

Is the error showing up earlier in your error chain then where you have probe #6 sitting now?

You need to do some more debugging to see exactly which function along your error change is raising this error.

I don't understand the comment on the diagram "To make sure the communication works even if the driver is not initialized."  Who put that there and why?  That seems like a hack.

(By the way, you don't need a separate tunnel for the error wire going into the case structure.  Connect the error wire to the case structure selector terminal, the "?")

[alright_meow]

The error is showing up at the property node, before probe 6. The comment was already there, this i havent modified this vi in anyway. This is exactly how i downloaded it from NI.

[RavensFan]

So can your device handle that property node?  What happens if you take it out?

You said something about a GPIB / Modbus interface.  Maybe it doesn't alike having the ASRL set.

[alright_meow]

I am assuming it can't, due to the error. I take out the property node, and it will time out on the VISA read.

[RavensFan]

You'll just have to read the manual for your device and see what it requires to make it work properly.

I still think there is something odd going on in the mixture of a GPIB interface with a Modbus protocol.

[mpencke]

what was the outcome of your debugging?

this is my situation:

I am having a  timeout error (-1073807339) see attachment . I have stuck 100msec delays before and after the read visa with no change. I am attempting to communicate with an F4 controller with a very simple vi (using NI WATLOW drivers). I am starting a profile, aborting a profile, current step, current temp. I started my project by validating hardware and I used Watview as a sanity check. The communication path is F4D (RS485) / RS485 to RS232 converter /RS232 to USB converter /PXI chassis.

During development the vi worked fine. After saving my project, I shutdown Labview, restarted labview, restarted my vi and then the MODBUS RTU RECIEVE message error (timeout). I did the usual check of comm port with MAX, revalidated hardware with Watview (verified the Watlow read the thermocouple), and still MODBUS RTU RECIEVE message error (timeout).

I have confirmed that there is a combination of opening my project, starting my vi, then starting the NI "CLOSE" vi, restarting my vi, which clears the timeout problem. If I were to close Labview and reopen my vi, problem reappears.

[alright_meow]

Sounds like you got further than i did with these. I never did get this figured out. I ended up making my own driver library for the Watlow F4. This way i could get the exact functionality that i needed out of them, without having to modify all of the existing drivers.