"VISA find resource" doesn't see cDAQ-9188

[rasraster]

Hi folks; I'm using LabVIEW 2009 with NI-DAQmx 2.3, and I have a cDAQ-9188 connected via Ethernet to the laptop running these programs.

MAX finds the cDAQ-9188, and I see it in the device names under the DAQmx System Property Node, but when I use the "VISA Find Resource" VI I can't find it as a VISA resource. I've used every search mode possible, but no luck. I should also mention that I've tried all the major expression strings I could, too, ranging from nothing to "?*" to "?*INSTR" etc.

Can anyone suggest why this might be happening, and what it would take to get the "VISA Find Resource" VI to find the cDAQ-9188?

Thanks in advance,

Rich

[Tom_W_[DE]]

Hey Rich-

The cDAQ-9188 is not a VISA resource; it is used with NI-DAQmx.  I suspect you're trying to use the device with NI-DAQmx Base (which uses VISA under the hood).  The cDAQ-9188 is only supported with NI-DAQmx on Windows machines.  I would suggest grabbing the newest version of NI-DAQmx and then trying to discover, Add, and Reserve your cDAQ-9188 in MAX.

Hopefully this helps-

[rasraster]

Hi Tom, 

Thanks for the quick reply!

Actually, I did add and reserve the device in MAX. All of the other devices I have that show up in MAX get listed in at least one of the search modes of the VISA Find Resource VI, and the documentation says that VISA is used for Ethernet (and TCPIP), so I assumed that the cDAQ-9188 would be a VISA resource too.

I think that there is some basic knowledge about all this that I am missing. I've looked through a bunch of literature, but haven't been able to figure out how all this - VISA, MAX, ... - fits together.

Rich

[Tom_W_[DE]]

Hey Rich-

MAX is just a configuration tool for NI software and hardware.  If you found it there and added and reserved it, you're well on your way.

VISA is a programming interface for lower-level development, like programming your device using TCP sockets-style programming if you are using a lower-level device API.

The cDAQ-9188 (and other cDAQ devices) are programmed using the higher-level NI-DAQmx API.  You can find examples online for various programming environments (LabVIEW and various text-based environments) or within the NI Example Finder if you are using an NI ADE.

[rasraster]

Thanks, Tom, that's helpful.

Perhaps I should back up a bit and describe what I'm trying to do.

We perform a variety of different tests, typically involving pressure transducers, power/voltage/current meters, temperature (TC and RTD) measurement, and several different types of flow instruments. We also use a lot of different devices, in different combinations, to do the same thing. What we grab from the shelf for a test depends on what's available.

So, we have three kinds of Yokogawa power meters, TCs and RTDs, two types of flow transducer (one gives pulses and the other has a linearizer), two types of cDAQ (9172 and 9188), and different cDAQ modules that can be plugged and played in each chassis. We don't want to have dozens of different VIs, to suit every possible combo of instrument and measurement. Instead, we want to choose what properties will be measured and then have LabVIEW be smart enough to detect the equipment that's connected and run the data acquisition accordingly. (Plus, tell us if we're missing some sort of sensor or controller.)

The first step in all this is to detect every piece of equipment attached to the laptop in question, but I'm having a devil of a time doing this programmatically. After a lot of exploration and trial and error I have written a VI to tell me what chasses are connected and which modules are in each of them, and it even gives me the name that MAX has assigned so that I can use that to start and control the instrument. But that VI can't get me the GPIB instruments. In contrast, the VISA Find Resource VI gets me the GPIB instruments, but it can't get me the cDAQ-9188. And both of them get fooled all the time between instruments that were once connected (but not anymore) and instruments that are currently connected.

I don't understand why this is so difficult to do well. Seems like there should be a reliable VI or two that gets all the instruments currently connected, correctly.

Thanks again for your help.

Rich

[JoshuaP]

I don't understand why this is so difficult to do well. Seems like there should be a reliable VI or two that gets all the instruments currently connected, correctly.

---

There is, its called NI System Configuration, which you can think of as the programmatic API for MAX.  If you just want to know what is connected to your system it is the API you should be using.  However, when it comes to performing actual measurements you will need to switch to DAQmx or NI-VISA depending on what hardware you are using.

http://www.ni.com/download/ni-system-configuration-5.6/4517/en/

Check out the Find Hardware example that is included with it.

[rasraster]

Thanks, Joshua. I hadn't heard of that software before. Unfortunately, it needs LabVIEW 2010 or above, and we have LabVIEW 2009.

Rich

[JÞB]

Exactly Joshua!  

The System Configuration API never really got the press it deserved.  It is extremely useful for cases such as this

You should consider an upgrade from 2009  BUT System Config 5.3.3 will install support for 2009

[rasraster]

It looks like System Configuration Version 5.0 is compatible with LabVIEW 2009. I'll give it a try.

Thanks!

Rich

[JÞB]

See my last edit 5.3.3 offers some enhancements you might want