Device stopped respond with serial poll status

[Jon.H]

Hi,

My system consists of a tester (Controller, addr 0) and a handler (device, addr 30). In normal operation, the tester perform serial poll continuously and obtained the serial poll status byte returned by the handler (please refer to without listen-only device.txt).

When I connect another GPIB listen-only device on to the existing bus, the handler stopped respond with the serial poll status byte and a timeout was occurred instead (please refer to With listen-only device.txt). Operation back to normal once the listen-only device is put to off-line.

The objective is to "snoop" between the communications of the tester and the handler. This listen-only device act as a listener at every GPIB address and it will be listening to the communications of the two to gather only the data bytes and not commands, but it should not interfere with the normal operation of the two. (note: I'm using the ibconfig options for IbcLON to configure the interface as a 'Listen-only' device).

What are the possible causes that the handler stopped respond with the serial poll status and any ways to overcome?

Thanks.

SY Heng

[Jon.H]

Sorry, missing attachments.

[LoganS]

Are those .txt files from the NI GPIB Analyzer?  Could you repost them as .cap files if that is the case?

[Jon.H]

Hi

Thanks you for responding to my email.

Yes, the two .txt files were exported from the NI GPIB Analyzer.

This forums dose not accepts .cap as a valid extension for an attachment.

Please find attached .zip which contains the .cap files for your review.

Thanks.

SY Heng

[LoganS]

Hmmm.  Have you verified with the hardware manual of the "listen-only" device that the IbcLON configuration option is all that is needed make it a listen only device?  Something is asserting NRFD before your instrument can assert the DAV signal, if I'm reading that correctly.  What instrument are you using?

Logan S.

[Jon.H]

Hi

Thanks you for respond.

My 'Listen-only' device was a PC with a plug-in PCI GPIB interface board which was configured as a non-CIC device.
Please refer to this links: http://digital.ni.com/public.nsf/websearch/5B150B37A272D13885256429008310B6?OpenDocument for configuring a GPIB interface to a listen-only state.

The instrument was a SEKIO-EPSON IC test handler.

Regards,

SY Heng