Scan for instruments finds instrument but does not respond

[Drec]

I recently had the task to reinstall the NImax software which connects to a Mitutoyo instrument.  The PCI-GPIB card was running before on driver version 2.1.0.3500 and installed with it a version of 2.2 of the Explorer.

I was unable to find this version, the closest version I could find was 2.2.0.3500 which installed a different explorer as well.  When scanning for the instrument, it could find the instrument but does not respond to the IDN query.  I can't seem to communicate with this device at all.  Is it possible that driver/explorer version would affect this?

[Collin M]

Did the instrument respond to *IDN? before you upgraded MAX? If it is not 4882 compliant than it may not respond to *IDN?. If MAX detects it during a scan for instruments that means it is responding to GPIB addressing commands. Have you tried using your original application instead of trying to manually communicate to the instrument?

[Drec]

With the 2.2 version of Explorer it seems to respond to the *IDN?.  It will report back the instrument's identity, where the new explorer does not.  When trying to use the instrument with the original software(Geomeasure), it reports that the CMM is off.

The only thing different between the two setups are, the original PC was a 600 MHz and the new one is at 2.7 GHz.  The original drivers and explorer are an older version that I can no longer find.  I contacted Mitituyo support and was informed that their software (GeoMeasure) would not work with the faster speed PC.  However, I believe my problem to be at the communcation level in the Explorer software, not Geomeasure.

[Dennis_Knutson]

The version of MAX has nothing to do with GPIB communication. It is the version of NI-GPIB that I suspect you are talking about and the speed of the pc can be a factor with older instruments. See this recent thread about the various options for slowing down GPIB bus communications. Is sounds like you got confirmation from the vendor that the instrument has problems. Their GeoMeasure program probably uses the same low level GPIB calls that you are using in MAX.

[Collin M]

One thing you could do is take the hard drive from the new 2.7GHz computer and use it in the older 600MHz computer. That will tell you if the problem is related the the speed of the computer or the software installation. It is not uncommon at all for systems to stop working when installed on a faster computer.

Also, can you run NI-Spy during the failure to see exactly what the failure is?

[Drec]

I do not have the pc at my location, so I am unable to run the Ni SPY.  The error message I would get back when trying to communicate would tell that it could not get a response from the instrument and to make sure it was properly connected and powered on.  I do not know if the PC speed is affecting this, when running the initial tests everything would pass fine.  I just run into the problem when trying to communicate with the instrument, or what sounds to be similar to a ping. 

One other odd symptom was that when I scan for the instruments, sometimes it would fail and sometimes it would find the instrument.  It would find the primary address of the instrument, but that is the only information that was being passed. 

Thanks for your help.

[MissyS]

Hi,

It seems that this problem is due to a timing issue, and that sometimes the timing is just right to allow it to communicate.

Does any of these suggestions posted (from Dennis and Collin) change the behavior you are seeing?

Regards,

[JasonSmith]

If you believe the problem is due to the newer version of the driver, you may visit the Legacy NI-488.2 Driver Request page to obtain version 2.1 of the driver.

We would recommend that you use the latest version of the driver supported by your operating system and hardware (See this list for details), but it could be useful to obtain version 2.1 for troubleshooting purposes.  I would recommend following the procedure below:

1. Install NI-488.2 version 2.4 (Assuming you are using Windows 2000 or XP), to test communication with the latest driver
2. If communication fails, uninstall NI-488.2 and install version 2.1
3. If communication is successful, contact your instrument manufacturer for possible updates to allow compatibility with the latest drivers.
4. If communication fails with 2.1, but it used to work, then there is something else wrong with the system.

Let us know the results of trying this, and we can provide further suggestions if needed.

-Jason S.