I have got an GPIB ENET and PCMCIA GPIB controllers installed in my notebook computer. How to use both controllers at the same time to control two different GPIB instruements in LabView?

[Roger CHAN]

I have to use both controllers at the same time because the two GPIB instruements are at two different locations very far away from each other.

The operating system I am using is Windows 98. LabView version is 5.0.

Both controllers work fine in my notebook.

Please help!

[jwf]

You should be able to open a seperate VISA session to each instrument. And use VISA reads and writes to communicate with the different instruments. I don't see any problem with this, I have done this several times. Is there a specific problem you are having?

[Roger CHAN]

Dear all,

I used to collect data from these two GPIB instruments separately with two notebook computers and two Labview programs. Both computers use PCMCIA GPIB controller to collect data from them.

With the new Ethernet network and new GPIB/ENET, I want to eliminate one notebook and collect data from these two instruments at the same time using just one computer.

Now, in one of the two computers, a GPIB/ENET and a PCMCIA GPIB controller is installed. The ENET is gpib0 and the PCMCIA controller is gpib1.

In my future setup, one of the instrument (PAD = 5) will be connected to the ENET and the other (PAD = 6) will be connected to the PCMCIA GPIB controllers. Can I control these two instruments with my existing Labview programs from this single note
book computer? If yes, please let me know how.

Regards,

Roger

[Dieter S]

Hello Roger,

This is similar to the other GPIB-ENET question that you had. LabVIEW will be able to communicate with each instrument, but you will need to modify your program to make sure that LabVIEW addresses each instrument correctly. If you have two GPIB controllers on your system, then one will have an interface name of GPIB0 and the other will have an interface name of GPIB1 (assuming they use the default interface names). Another way of looking at this is that you have two General Purpose Interface Buses on your computer, bus 0 and bus 1.

By default, the GPIB functions in LabVIEW refer to bus 0 (GPIB0). In order to communicate with bus 1 (GPIB1), you will need to use the correct naming convention with those GPIB functions. There is an article in the NI D
eveloper Zone (http://www.ni.com/zone) that covers this topic. Go to the main NI Developer Zone page and select the link for "Resource Library". Then take the link for "GPIB", which will take you to the GPIB Resource Library. Click the link for "General" and then click the link for the "How to Enter GPIB Primary and Secondary Addresses in LabVIEW" tutorial. Here is a direct link to that tutorial: http://zone.ni.com/devzone/devzoneweb.nsf/opendoc?openagent&640A93B98F01F425862568230060307C

Another source for this information is the LabVIEW Online Help for the GPIB functions(accessible from the Help menu in LabVIEW).

I hope this has been helpful, but I'll provide more details if you need them.

Best Regards,
Dieter

Dieter Schweiss
Applications Engineer
National Instruments

[Ryan_M]

Both of the GPIB controllers are supported by the same driver in Win98 so the only difference between accessing the two busses is in how you address it. For exmple, if your system configuration is such that the PCMCIA-GPIB is GPIB0 and the GPIB-ENET is setup as GPIB1, the you would access devices using VISA with either a GPIB0::PAD::INSTR or GPIB1::PAD::INSTR depending on if you want to access the ENET or the PCMCIA interface. Please note that PAD would be the primary address of your instrument.