LabVIEW
Configuring DAQ channels through LabView program
I would suggest to start using DAQmx instead of the traditional NI-DAQ drivers. Soon, the NI-DAQ drivers will no longer be supported and you'll need to learn to use them anyway. DAQmx is a much better driver, and it's actually easier to setup and much more efficient. Of course, if you're not using LabVIEW 7.0 or 7.1, kindly ignore this message.
The attached VI uses DAQmx to programatically build a DAQmx task to scan 8 channels on a PCI-6025E every 250ms. It uses some DAQmx property nodes to query the system to see what devices are installed, so if you run it on a different system that has the wanted DAQ card setup as a different device number, this will catch it and build the correct task.
Ed
The attached VI uses DAQmx to programatically build a DAQmx task to scan 8 channels on a PCI-6025E every 250ms. It uses some DAQmx property nodes to query the system to see what devices are installed, so if you run it on a different system that has the wanted DAQ card setup as a different device number, this will catch it and build the correct task.
Ed
Using the Abort button to stop your VI is like using a tree to stop your car. It works, but there may be consequences.
One of the great things about DAQmx is that there are only 4 basic VI's to learn to use. The Configure, Read, Write and Stop. The same Configure VI that was used to setup the analog input channels can be used to setup analog output, digital in/out and counter in/out.
The small menu on the bottom of the VI is actually a listing of all the different operations that this single polymorphic VI can do. Click on the down arrow and you'll see what I mean.
I've modified the example to read DIO lines 0-3 and write to lines 4-7 on Port 0. Again it programatically builds the channel list so it will always refer to the correct device. To create individual channels for a digital line, you first specify the device, then the port, then the line or lines. Example, to create a task for lines 4-7 on port 0, you would use "Dev1/port0/line4:7".
Notice that the "DAQmx Create Channel.vi" is the same one used in the analog input configuration, but with different polymorphic selections. Also note the "DAQmx Read.vi" is the same except for the selector.
Ed
The small menu on the bottom of the VI is actually a listing of all the different operations that this single polymorphic VI can do. Click on the down arrow and you'll see what I mean.
I've modified the example to read DIO lines 0-3 and write to lines 4-7 on Port 0. Again it programatically builds the channel list so it will always refer to the correct device. To create individual channels for a digital line, you first specify the device, then the port, then the line or lines. Example, to create a task for lines 4-7 on port 0, you would use "Dev1/port0/line4:7".
Notice that the "DAQmx Create Channel.vi" is the same one used in the analog input configuration, but with different polymorphic selections. Also note the "DAQmx Read.vi" is the same except for the selector.
Ed
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My guess would be you have the digital configuration incorrect. This can be a bit tricky as it's not always clear which choice to select. I know, I said this was easier, but there is a learning curve.
There's an input on the Digital Configure called "Line Gouping". In the last example I posted, this was set to create a separate channel for each line that was specified in the task. This lets you read or write a boolean array. If you are specifing an entire port/ports with no individual lines specified, you must change this to create a single channel for all lines. You must then also select the correct digital read or write operation from the polymorphic selector on the read/write VI.
The attached example configures 5 separate tasks on the three cards you mention. The two new tasks on the two DIO cards are showing a port selection setup.
I hope this gets you where you need to be.
Ed
There's an input on the Digital Configure called "Line Gouping". In the last example I posted, this was set to create a separate channel for each line that was specified in the task. This lets you read or write a boolean array. If you are specifing an entire port/ports with no individual lines specified, you must change this to create a single channel for all lines. You must then also select the correct digital read or write operation from the polymorphic selector on the read/write VI.
The attached example configures 5 separate tasks on the three cards you mention. The two new tasks on the two DIO cards are showing a port selection setup.
I hope this gets you where you need to be.
Ed
