Multifunction DAQ

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change event for multiple digital lines

Hi,
 
I'm having a problem with the change events of my DAQ card (NI-DAQ-6515) which i'm getting very soon. I'm allready programming the program because it is for a replacement of another system which has broken down.
 
The DAQ card is connected to 16 seperate digital outputs of devices which correspond with an open or closed state of those devices. At the moment a device changes its state i want to detect it with a change event which must be possible with this type of card. The problem is with the "DAQmx timing.vi" I can detect a change event but only for 1 channel and make an event of this with the register event node. Can this be done with all channels, so that if any digital input channel changes an event is generated and that i know which channel has generated that even.
 
Any help is welcome.
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Message 1 of 5
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You can check the following link:

http://zone.ni.com/devzone/cda/tut/p/id/4102

There is no property to check which channel caused the event.

Regards,

Bas van Dijke
AE Netherlands

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The problem is not only that i need to detect which channel changes but if any channel changes of the 16 channels. I was afraid i wouldn't be able to detect which channel created the change event. But that isn't a major problem. What is a problem is that with the DaqMX timing.vi you can only input one change channel while i need 16. I was wondering if you can just put 16 DaqMX timing.vi behind one another with 16 different channels to monitor change events, or if that will only result in the monitoring of the latest added change event. Unfortunatly i haven't received the DAQ card yet from NI, so i can't try it and find out, and because the project must be finished before the end of the year i don't have the luxary to wait on the DAq card before programming the program.
 
 
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Hi,
 
as you can see in the document linked in my previous post, you can see that you can input one channel to the timing vi, but that that channel can contain 16 lines. So it isn't necessary to place 16 timing vi's parallel.
 
Did you know that you can simulate your device in MAX?
 
Regards,
 
Bas
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Hi,

I had seen the example but overlooked the fact that besides channels you could also select an entire port to monitor. This is enough for me to make my program working. Thanks very much. I've allready simulated my device but unfortunatly simulated device can't handle change events while they don't generate events.

 

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