How do I create a pure C# connection to Ethernet based CompactDAQ (9191)

[Larover88]

I would like to use the pure C# way to communicate with CompactDAQ devices that are on our local lan.

So no NI MAX - only native C# using NationalInstruments.DAQmx napespace (+Common :-).

I can't find any examples etc. only the usual configuration setups - how do I go from IPnumber only (or perhaps event through discovery)

It is needed for some automatic configuration setups where the hardware is being swapped from time to time by an operator.

[A.Rohde]

Hi Larover 88

Did you find a solution to your problem?

There is as far as I know no built in functions for auto discovery of DAQ devices. But if you have configured them with an IP address then it is faily simple.

1) First you need to reserve the chassis to your PC and add it. Take a look at these two functions in the manual:

NationalInstruments.DAQmx.DaqSystem.AddNetworkDevice()

NationalInstruments.DAQmx.Device.ReserveNetworkDevice()

2) After you have added the device and reserved it you can use it as a traditional DAQ device. Like in this articles

http://www.ni.com/white-paper/5409/en/#toc4

http://www.ni.com/white-paper/2835/en/

Best Regards

Anders Rohde

Applications Engineer

National Instruments Denmark

[Tom_W_[DE]]

As Anders mentioned, you can reference the chassis by IP address or hostname when using the AddNetworkDevice() method.  After that, it will have a DAQmx device name (like cDAQ9191-<serial number>) and you can use the DAQmx functions as if it was a device connected directly to the PC.

Just to avoid any possible confusion from ambiguity: once the chassis is added and reserved, you can use it as you might have traditionally used other NI-DAQmx devices.  It can not be used with the Traditional NI-DAQ driver, though.

For programmatic discovery and configuration, you can consider the NI System Configuration API.  Here is a quick reference that claims support for Visual Studio environments, though I can't vouch for whether or not they specifically provide a C# API.  So you may need to do some integration work to call into one of the supported APIs from your application.

[Larover88]

I did find a partial solution - I ended up reserving the device in NIMAX and then create the rest in C#.

Is there a best practice paper / white paper for .NET (or C++) interfacing - describing the intended interaction between the different classes?

It seems to me that the focus of the NI documentation effort has switched greatly to LabView which in the end caused the pure code based work to lag behind a bit when comparing to 10 years ago.

[SMeesters]

It can be done in fully in code:

DaqSystem.Local.AddNetworkDevice("169.254.228.179", "cDAQ9188XT", 10)
DaqSystem.Local.LoadDevice("cDAQ9188XT").ReserveNetworkDevice()

This is done in VB.NET but should be easy to port it to C#

[TomMartin-JetSoft.co.uk]

This seems to be a bit of an oversight on NI's part.

I used Anders suggestion but had to modify it slightly to get it to work:

            Device device = NationalInstruments.DAQmx.DaqSystem.Local.AddNetworkDevice("169.254.69.102", "cDAQ9184", 30);
            device.SelfTest();

Tom Martin

Software Engineer

JetSoft.co.uk