VISA error code -1073807253

[NyteFall]

The reason I'm testing the function generator with the serial before I test the flow controller is that I know the LabVIEW program for the function generator works. Since there might be an error in the flow controller code, I'm testing serial communication with something that I know is functional so I can rule out faulty code as one of the problems.

I am picking up a new cable today which I've been told has been successfully used for RS232 communication before.  Hopefully the new cable should allow me to use the most up-to-date drivers available, which should be fine with Windows 10 (theoretically).

[Dennis_Knutson]

You don't need any driver to test communication. Or any LabVIEW code. A few simple commands with MAX or a terminal emulation program such as putty I'd all that you require.

[NyteFall]

Just an update on the progress:

Using the correct adapter helped. I am now using the Sabrent Model: USB-2920 adapter (no longer using prolific drivers from 2007).  That got me a little further through the program. I am now throwing an error while running the function "Scan From String" (boxed in the image attached).  I keep getting "error 1: Input character invalid". The error is thrown in both instances of the "Scan From String" function.

For some reason I cannot get an indicator to output the function's input so I'm having trouble figuring out what character is invalid.  I've tried setting the indicator (named: "read buffer") to read backslash codes as NI support recommended, but that still didn't work.

Tomorrow I'm going to try to set-up a "search and replace" function to remove all invalid characters to try to fix this problem.

If anyone has any thoughts on a different way to get around this, please let me know 🙂

Thanks again to everyone who has been helping me figure out what's going wrong! 🙂

[Sam_Sharp · Accepted solution]

Ok, so you send a command and then immediately read the number of bytes at the port. What about giving the instrument a chance to reply? If you probe the bytes at port and serial out of the VISA read - you've probably not got any data (reading 0 bytes?).

Does the device have a termination character (e.g. newline?), if so - you should turn that on in your configure serial port VI and remove the bytes at port so the visa read will wait until it receives the termination character and returns the data.

If you don't want to use the termination character, any time the scan from string doesn't find a match, it will return an error - so you may need to ignore that error until you receive the \r\n. Is your format specifier for the scan from string in slash codes display? If not, you're looking for the literal characters "\", "r", "\", "n" rather than a line feed & carriage return.

[amazed]

side note, assuming you are communicating, i would use the software handshake cable wired as shown in the manual.  You will have more reliable communication.   The 647 automatically senses this cable on pwr up.