07-30-2009 07:16 PM
Hello Everybody,
I've been trying to code a subroutine that produces a TTL trigger signal. When I had it in test vi, which is smaller then then one I need to insert to, everything worked fine. After I inserted this subroutine into an original program I got the following message:
"Error -200429 occurred at DAQmx Write (Digital Bool 1Line 1Point).vi:3
Possible reason(s):
Measurements: Value passed to the Task/Channels In control is an empty string (or I/O control).
The value must refer to a valid task or valid channels."
I tried to understand the reason why I am getting this message, but apparently with no luck.
The way how program should work is as follows, I created a case structure inside while loop to be able to gather data either manually or automatically.
For <<manual>> case, I placed a switch that should turn on trigger along with "write to file" option, that record data from load cell/motors.
For <<automatic>> case I wanted to create a threshold, passing which turns on <<trigger along with "write to file">>, otherwise do nothing.
I have a feeling that there is some logical error and I am not completely following how data flows should be organized in the presence of multiple structures.
I hope somebody with a good eye on such problems can give a hand.
Thanks in advance
Oleks
Solved! Go to Solution.
07-30-2009 08:01 PM
08-03-2009 04:04 PM
Thanks Adnan,
Thats was the problem I had. In the test program I had "Clear Task" outside of the loop, but when I start putting everything togather I guess I was not very careful.
Thank you again for the help!
Oleks