VISA Read Timeout Error When Using Flow BUS protocol

[Red_CCF]

Hi

I am currently using the Flow BUS protocol for an MFC and I keep getting a VISA Read Timeout error:

Error -1073807339 occurred at VISA Read in Send Setpoint.VI->test.vi

Possible reason(s):

VISA:  (Hex 0xBFFF0015) Timeout expired before operation completed.

I extracted part of the code and attached it to this post. Basically whenever I hit OK to send a setpoint VISA Read just times out. I tried using the sub  VI that is responsible for sending setpoint and it was fine (when I manually copied and pasted the ASCII codes) but when I run the overall function it times out.

Any help is appreciated

Thanks

[Red_CCF]

I posted screenshots of what I see when I run the Send Setpoint.vi as a sub VI (file Bad.png) and when I run the VI independently (file Good.png) using the same commands.

[Red_CCF]

I think I know the error but I'm unsure of how to correct it.

It seems that when I run the Send Setpoint as a sub VI, the '\' Code Display changes to :06800101210855\\r\\n, which is displayed after I click STOP when the timeout error message shows up. However, if I manually change it to :06800101210855\r\n in the  '\' Code Display (which, when switched to Normal Display becomes :06800101210855 ), an I run the Send Setpoint VI independently (not as a sub VI) everything runs fine. So basically I would like to know if it's possible to send something with ending \r\n when viewed in '\' Code Display.

[Dennis_Knutson · Accepted solution]

If you have any string control or constant that you enter a \r\n into, you MUST have '\' Codes Display turned on in order to enter the actual control characters. If you enable '\' Codes Display and see \\r\\n, then you have used Normal Display to enter the characters.

[Red_CCF]

Thank you very much; I enabled \ Code Display for everything but forgot about the string constant

[Red_CCF]

Hi

I'm getting a different VISA Read error now for some reason. Now for some reason, I don't read anything after I send the setpoint. However, again when I run the send setpoint by itself I do get something back but when I run it in the bigger program I get nothing, and this ends up being an error in my error checker.

[margasan]

Hi

I believe your error is related with the termination characters in your program. Try to check that and if you get an specific error code, post it so I can give you more information. 

Have a good day!