Monitor a device using the same device

[P. Jack]

I have an application that uses NIDAQCard-DIO24. It is already an executable VI built in LabVIEW 5.1.1 and I do not have the original VIs with block diagram.

How can I capture everything that this application writes/reads using the same card?

[becktho]

Hi

I'm not sure but I think this is not possible.

If you have your executable running, any other vi won't access this device because it is already in use.

Thomas

[LV_Pro]

I agree with becktho, if you try and access a DAQ card being used by another application, or even another VI you will get an error telling you roughly "this resource is busy".


Putnam Monroe

[becktho]

It is the same as the serial port.

Just start one terminal which opens com1 and then start another termin and try to open com1 again.
You'll get a message that com1 is not accessible.

Thomas

[P. Jack]

Thanks for your reply.

However, there is a function in one of DAQ's dll called DAQ_monitor. I think it can help my concern but I am not that good at this level.

Can you dig deeper?

[Ayman K]

Hello,

The DAQ cards' resources will be reserved since your EXE is using that DAQ card, and the function that you plan to use will not execute properly considering that you will write a program (text-based)to use the function.

[P. Jack]

I am planning to use Call Library Function.

Anyway, I am not giving up this topic. I strongly believe that it can be done but I am looking forward a very hard working days ahead of me. I'll just inform you if I'm successful.

[Ben]

You do not go for the easy stuff do you?

If you REALLY want to walk that path, I will offer the only hint that I can.

Re-write the dll that is called by NI-DAQ.

Your re-write will have to echo the calls to the original dll and add the extra functionality of leting you eaves drop on the activity.

In the meanwhile, could you share with us what the LV 5.1.1 program does that you do not want to re-write?

Who know, maybe one of wrote it and still has the source.

Ben