02-28-2013 10:38 AM
Hi Guys,
I have an NI 9205 mounted in an NI cDAQ-9178 chassis which I'm trying to use to supply an analogue trigger to a data capture task I'm implementing. I followed the instructions in http://digital.ni.com/public.nsf/allkb/851828B06A20E01B862571DA0005591A to set up the NI9205 to provide a digital trigger to a second input channel when the analogue level exceeds a certain threshold. However, when I run the vi I get the following error:
Error -89131 occurred at DAQmx Start Task.vi:1
Possible reason(s):
An attempt has been made to perform a route when the source and the destination are the same terminal.
In many cases, such as when configuring an external clock or a counter source, you must select a PFI, PXI Trigger, or RTSI line as the source terminal.
Property: Start.DigEdge.Src
Property: Start.DigEdge.Edge
Source Device: cDAQ1
Source Terminal: ai/StartTrigger
Task Name: _unnamedTask<31>
I'm not sure why this is happening, since I'm following the white paper instructions. Does anyone have any ideas? I've uploaded the VI for you to take a look at.
RB
03-25-2013 09:47 AM
Hi RottenBorough,
The error you are getting clearly refers to the ‘Start.DigEdge.Src’ property, which means the ‘DaqMx start trigger’ polymorphic VI is used in the ‘start digital edge’ configuration in your code. I could not find this VI used in this configuration in the file you have attached. Are you doing this in another part of your code? Also I have the following questions after going through your VI:
1) Is there any specifc reason why you are generating a counter pulse output and not using it? I feel you would not need this if you are just trying to trigger another task using analog triggering.
2) Also, I noticed that you have not used the cDAQ internal digital edge ( for eg: /cDAQ4/ai/Start Trigger) to trigger another task (as mentioned in the KnowledgeBase article).
One reason I can think of for this error is, you might be trying to set a source for your ‘DaqMx start trigger’ through the external terminal, while it has already been configured to use this source because of the option selected through the drop down arrow of this polymorphic VI. But as I have mentioned before, I do not see you setting up digital edge triggering in the code you have attached. It is worth checking if you are doing such a thing in another part of your code.
Thanks and Regards,