Hello, I'm attempting to communicate with a serial device via VISA and have been stuck for a while trying to figure out why my program hangs at the VISA Read VI (it hangs until it times out). Increasing the VISA session timeout value hasn't helped - it merely causes the program to hang for longer before it times out.
I'll attempt to provide as much information as I can, so below I'm posting screenshots of my front panel and block diagram and below that an explanation of the operation of the program:
http://i.imgur.com/IdHnl6K.jpg
http://i.imgur.com/2RSK2vX.jpg
This program is intended to trigger a case structure based upon the iteration value of the while loop that encases it for as many times as the value "number of steps" inputted on the front panel. Within each case of the case structure are a series of "serial device command" string concatenations which are tunelled out and passed to the VISA Write VI. From there the program is meant to read back the serial response (a string represenation of a floating point number ie. 2.0000) which is converted to numeric form and added to an array to store the response value from each iteration of the encasing while loop.
All the commands written execute just fine as evidenced by the operation of the serial device to which I'm writing and each "error out" is "OK" (including the Visa Write error out) until the Visa Read error out. When running the program and highlighting execution, the program simply hangs after reaching Visa Read (all the wires coming out of it are gray) until the VISA session timeout is reached at which point it [i]actually passes out the value[/i] it was supposed to read (ie. 2.0000), which gets stored into the array as desired, while putting out the error:
Error -1073807339 occurred at VISA Read in LabVIEW Delay Stage.vi
Possible reason(s):
VISA: (Hex 0xBFFF0015) Timeout expired before operation completed.
and consequently ending the program (the while loop is not executed again).
Any advice would be very much appreciated. I must admit that I'm a relative rookie when it comes to both Labview and serial communication, so I encourage you to treat me like a 5 year old. If you require any further information I'll be happy to try my best to provide it.
Note: I'm aware I probably don't need the execution structures within the case structures, but they're working so I've decided not to tamper with it for now.