How to connect 1 DAQ rack to 2 computers?

[mgnz]

Hi all,

I have two devices which I want to control from two separate laptops. Can I use one DAQ rack to do it? Devices will use separate channels or modules.

Thanks in advance
Gregory

[KRojas]

Hello there,

Could you share your DAQ rack model number?

Thanks!

[mgnz]

Hi,
I have cDAQ-9178 and cDAQ-9174

I can consider buying a different one if there will be an ability to communicate with two or three computers.

Thanks!

[Dane.S]

One thing I wanted to ensure you saw was the following KB:

https://knowledge.ni.com/KnowledgeArticleDetails?id=kA00Z000000P6xUSAS

[mgnz]

Hey,

Thanks for your message.

So basically seems like it's impossible to share one chassis between two computers... 

[_Bryan]

Not impossible, but it would take more programming and more work.  The easiest and quickest is to have DAQ setup for each laptop.  You have not explained why you want to use 2 laptops, so nobody has any idea on what else could be suggested to help you out.

You will find that giving more details in your questions will get you better answers.

[adrub]

Hey,

I'm working on the same project with mgnz.

Basically, we've built a couple devices which we want to test simultaneously - n operators, n laptops, n devices. We are not using all slots in chassis and not all channels in modules. So would be nice to reduce some costs and needed space by connecting more than one device to the chassis. But we still need two/more separate laptops.

And here is our question: Is it possible?

Cheers,

[_Bryan]

Yes it is possible, just not straight forward or ideal depending on what you are testing.  Since only one computer can connect to a DAQ device at a time you would need to have a program always running on one computer to control the all the DAQ I/O.  Then each test setup/laptop would need a program that communicates with the program controlling the DAQ I/O to send and receive data needed for the test.

You also need to make sure that one laptop/test can only read/write with specific channels.  You do not want another test taking control of a different test by accident.  You also need to be aware that if the one program that is controlling the DAQ has an error/breaks or just dies it will effect all the tests that are using it for I/O.  Also if you need to make a change to the one program connected to the DAQ you will need to stop all the tests that are connected to it.

You also need all the computers on the same network so they can access data from the main DAQ program.  Then you might want to think about what happens if there are network issues with any of the computers?  Do all the tests just keep running with no control and possibly damage equipment?

So it can get complicated and time consuming to do it correctly and I have only mentioned a few of the possible issues above.  Why not just get a desktop with a DAQ card for each test setup?  Then each test will be independent and the programs will be much easier and straight forward to write.

[_Bryan]

In the long run it would probably be more cost effective to purchase the correct equipment for each test station.  The systems would be up and running faster, the man hours required for programming and testing would be reduced and you would have more flexibility with testing.

Good luck.