TNT488 GPIB communication problem

[22online]

Hello,

I use the IC TNT488 for a GPIB communication.

I cannot establish the communication when I use the NI-488-02 Communicator software

I am able to send commands on the GPIB bus, but I am not able to receive a command.

If I use a Labview (ver 6.0) I have not problem (read/write is OK)

Any idea for solviong this problem ? (hardware, software ...))

Thank you !!

[BenjaminR]

Hello 22online,

Thanks for posting on the National Instruments Forum.

Can you tell me if you receive an error? If yes, can you send the error code?

If you wrote to your instrument without an error being returned by the write, you can reasonably assume that your written message was properly sent to the instrument due to the 3-wire handshake of GPIB. Now, you should perform a read (IBRD function call) to ask the instrument for a response. If you receive an error on a read, it will most likely be an EABO (abort) due to a TIMO condition. This indicates that the GPIB controller board was waiting for a response from the instrument but that response never came.
Things to check:

• The command that you previously wrote to your instrument. If you wrote an invalid command, the instrument may not respond with anything at all. See your instrument's user manual or contact its manufacturer for a simple command to send it. Many instruments will respond to "*IDN?" or "ID" (without the quotes), but a large number will not respond to these basic identification commands.
• The termination method used on your write string. There are two main ways to terminate data messages sent to instruments: assert the EOI (End or Identify) line on the GPIB with the last byte of the transmission, or send an EOS (End of String) character at the end (usually, this is a carriage return or a linefeed, both nonprintable characters. You can usually indicate them by "\r" or "\n" respectively, though this varies by application). The default termination for the National Instruments GPIB driver software is to assert the EOI line with the last character sent on GPIB writes. If your device requires a termination character, add it to the end of the string that you write to the instrument. You can change the EOI setting by making driver calls (see IBCONFIG) or in the GPIB Configuration utility (MAX in Windows, GPIB Explorer on other Operating Systems)

Let me know if you have any questions.