Upgrading GPIB-232CT-A to GPIB-RS232

[Raymond_T]

Hi,

Do to the system upgrade, I have replaced GPIB-232CT-A to GPIB-RS232. I am trying to write and read commands to a DMM through this GPIB-serial port convertor, "GPIB-RS232, my hardward configuration is as following, computer (Labview) <serial port> GPIB-RS232 in S mode < GPIB > DMM. The system worked well with labview functions, "GPIB Write" and "GPIB Read", but doesn't work once GPIB-232CT-A is replaced with GPIB-RS232.  The error associated with this problem is " GPIB Write returned error code: EDVR: Error connection to driver or device".

 Can anyone help me with this problem?

Thanks,

Raymond

[StevieZ]

Raymond,

Can you open a "Communicate with Instrument" window under Measurement & Automation Explorer to try to communicate with your device this method. If you do not see your instrument there click on your card and click the button that says "Scan for Instruments". This should also automatically set the Primary Addresses of the instruments which could be causing problems.

In the "Communicate with Instrument" dialog box Query a simple "*IDN?" and see if the same error is returned. Also, insure that you are using the correct termination character(s). The default terminator characters are \r\n, some devices require a different combination.

Regards,

Steven Zittrower

Applications Engineer

National Instruments

http://www.ni.com/support

[Steven_T]

Raymond,

What mode are you using and was the GPIB-232CT-A connected to your system (which ports where connected to which equpment)?

I would also like to know the software that you were using to communicate to the GPIB-232CT-A and GPIB-RS232 (were you using a GPIB driver, which one?).  If they were configured the same way, they should be interchangeable.

Thanks,

Steven T.

[Raymond_T]

Hi Steven,

Both GPIB-232CT-A and GPIB-RS232 were configurated in S mode. They are connected to a computer which acts like a controller throught serial port (COM 1), and the Digital Multi-meter is connect to the converters through GPIB. They basically were configured in the same way. I am using labview 6 and simply with two GIPB functions, "GPIB write" and "GPIB read", to communicate with the Digital Multi-meter. However, I have a question regarding these GPIB functions. For example, If the labview is trying to send a command to this digital multi-meter via this GPIB Write function, how does labview know which computer port the command is sent to, since I dont have a GPIB port on my computer?

Thanks,

Raymond

[Steven_T]

Raymond,

The GPIB-RS232 and GPIB-232CT-A are not supported with the LabVIEW GPIB VIs.  I would recommend downloading the package here.  It provides GPIB type VIs for communicating in S Mode.

http://zone.ni.com/devzone/cda/epd/p/id/5978 

I hope this helps,

Steven T.

[Raymond_T]

Hi Steven,   is this CompactRIO compatible with Labview 6?, cuz i am using Labview 6 instead of 8.

Thanks,

Raymond

[Dennis_Knutson]

The example code has nothing to do with cRIO. The example mentions it because it has a serial interface. The example VIs are written in 8.0 though so you would need to get them down converted. Download the VIs and ask for help on the LabVIEW board. Be sure to attach the VIs.