GPIB connectivity

[noobie_programmer]

Dear Sir:

     Can you please help me understand the general rules for GPIB connectivity to test instruments?  Specifically, hardware and software requirements which should guarantee connectivity.

      I thought I had a general understanding of GPIB card connectivity with regard to test instruments until I had a problem with connecting to a TEKTRONIX 784D oscilloscope.

      I was under the impression that an advertised 488.2 compliant test instrument should be able to communicate to any 488.2 GPIB card as long as OS driver requirements had been met.  However, this was not the case when I connected the 784D scope to a PCI-GPIB card.

      The TEK 784D oscilloscope manual asserts that a GPIB PCII/IIA card was used to establish connectivity. 

      When I look at a GPIB connector - they all look the same, what is the difference at the physical connection point between a PCI GPIB connector and a PCIIA GPIB connector (if any)?

       My question is, is the hardware -GPIB card type an initial requirement which must be met to establish connectivity, or does a software solution exist which can establish connectivity?   Can my PCI-GPIB card be configured to appear to the TEK scope to be a PCIIA card through software (driver installation)?  

[Dennis_Knutson]

I don't quite understand what you are asking about. There is absolutely no difference in the GPIB connectors for the PCI or PCII/IIA cards. The instrument itself has no idea what type of GPIB controller it is connected to. I don't see why you should not be able to use the PCI-GPIB card. What exactly happens when you do a scan for instruments in MAX? If the instrument is found, what error do you get when you try to communicate?

[crossrulz]

Are there any other instruments also connected to the bus?  Maybe you have a duplicate address.

I've ran into some instruments that you have to manually enable the GPIB in order for it to communicate.

As far as PCI vs PCIIA, a GPIB controller is a GPIB controller.  It doesn't matter how it is connected to the computer.

[noobie_programmer]

MAX never sees the 784D oscilloscope and I have all the options installed on the unit.

[noobie_programmer]

I tried to communicate with the device will all other devices disabled.    The possibility of duplicate gpib addresses is eliminated, but still no connectivity.

I am a C programmer, are there any code commands you could send me to troubleshoot this condition?

I just bought a GPIB analyzer  and I am learning how to use it.   If there is a sequence of commands you could input that could do the trick, I would welcome this information.

[Dennis_Knutson]

The only times I've seen this happen is with a bad instrument.

I you turn on NI-Spy, you can capture the low level GPIB commands that MAX uses when it attempts to detect an instrument.

[noobie_programmer]

Dear Dennis;

      There actually exist lower level commands on the bus that NI SPY suppresses. 

       I see commands such as LAD = listen address and interface clear.

       I am trying to correspond with TEK again.  I want to see if they can send me their instrument drivers.  Their website is so damn inconvenient to use it is unbelievable.   There are two separate accounts at TEK and specific e-mail addresses are not allowed.   I will get back to this again.   It is possible some file corruption exists.

[crossrulz]

You can use the LabVIEW Instrument Driver Finder to download the drivers.

[crossrulz]

From the NI site:Tektronix TDS784D Driver

[Dennis_Knutson]

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@noobie_programmer wrote:

Dear Dennis;

      There actually exist lower level commands on the bus that NI SPY suppresses. 

       I see commands such as LAD = listen address and interface clear.

       I am trying to correspond with TEK again.  I want to see if they can send me their instrument drivers.  Their website is so damn inconvenient to use it is unbelievable.   There are two separate accounts at TEK and specific e-mail addresses are not allowed.   I will get back to this again.   It is possible some file corruption exists.

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What low level commands do you think NI-Spy is suppressing?

Instrument drivers will do no good unless MAX can actually detect the instrument.