Error 1073807343 with LV example "basic 2 port serial write and read"

[sarah83]

Hi!

If I run my .vi (e.g. only button test 1) I everytime get a the error 1073807343 timeout (1073807339).
I can't follow this errors.
If I run all together the first is ok, but then I get the messages.

Message Edited by Support on 05-11-2005 07:30 AM

[Ray.R]

The error seems to point to a VISA detection or read error..

I don't have LV installed on this machine, so I couldn't look at your attachment.

Which LV are you using? and what VISA?

Do you have MAX (Measurement & Automation Explorer) installed? If so, do you see the serial port?

Also, are you able to communicate with your target (UUT / instrument) using a sw such as HyperTerminal or ProCOMM?

🙂

JLV

[sarah83]

Hi Joe,

I think Visa read could be the problem, but I can't understand.
I cut out all but the write part (and config) and tested with the programm "realterm" if there are some values. Right, this run.
Now I cut out all but read, run realterm to write but nothing works.

Everytime the problem is the Visa read in the rs232.vi (see attachment).
The code runs until this point and then there is an error.

There is an anomaly. Sometimes at the first run the rs232_neu.vi runs without an error.
But if I make a modification in string to write, the error is back.
If I send nothing and configure "0" bytes to read there is no error, too.

I using LV 7.1.1
Visa 3.1

Yes I have MAX and I could see all ports.
As I said I had test the ports without LV, only with "realterm" and there is no problem.
And I can send data over LV from one port to realterm. (3 to 4 and 4 to 3; 5 to 6 and 6 to 5)
But can't read.

[Dennis_Knutson]

You've got a couple of problems. One thing I see is that you are not sending a termination character with your VISA writes. If all you are doing right now is a loopback test, that should be okay but most instruments require either a CR or LF to terminate a command and get a response back. Second major issue is that in your RS232 subVI, you are configuring two separate com ports and doing a write and read in parallel. The read could actually be done before the write. A basic tenet of LabVEWI is dataflow. Unless there is data connecting operations, the LabVEIW compiler attempts to execute things in parallel. There is no guarantee that your write will be done before the read because you only do a data connection after the operations. Moving one function to the top or left side of another operation means nothing. Connecting the error out of your VISA Write to the error in of either the second VISA Configure Serial Port or the error in of your VISA Read will ensure things get done in the correct order. A better data flow might be the two VISA Configure Serial Port, then the VISA WRite and finally the VISA Read. It should look similar to the picture in the attachment.