Re: ibln() fails on Agilent 82357a
Frank Mori Hess <[email protected]>
| Newsgroups | gmane.linux.hardware.gpib.general |
|---|---|
| Message-ID | <CAJz5Opc4h3MrvzdGTjeby8c5Lcehx23Uf15YRvJ5HR=zstna+g@mail.gmail.com> |
It might be due to the gpib transceiver, which sits between the actual gpib bus lines and the gpib chip. The transceiver controls whether the various bus lines are inputs or outputs. The transceiver I'm looking at configures NDAC as an output/input based on whether the gpib chip is talker. So it seems as a practical matter we do need to address the controller as talker to read the NDAC line. The 488.2 FindListeners protocol doesn't include any mention of talker addressing, only listener addressing, which you could take to mean that addressing the controller as talker shouldn't cause any problems with the protocol. We should probably mention in the docs that the functions change the talk state of the controller though. On Mon, Jul 22, 2019 at 4:54 PM dave penkler <[email protected]> wrote: > > Hi Dirk, > Does using ibcmd() to address the board as talker before calling ibln() not work for you ? > AFAICT there should be no issue to add the one-line patch as standard behaviour for the 82357a but I don't know whether it could adversely affect other card types. > -Dave > > On Mon, 22 Jul 2019 at 20:35, Dirk Niggemann <[email protected]> wrote: >> >> It looks like the Agilent 82357a has the same issue as some of Measurement Computing cb7210.2 chips (even though it purports to e tms9914 internally) and can't read the state of the NDAC line unless addressed to talk. >> There was a simple one-line patch published by Bernhard Heibler in 2004 on this list that still applies today. >> >> Adding the single line to add a MTA command in listenerFound in ibFindLstn.c resolves the issue. >> >> Can we make this either the standard behaviour or add some kind of option in gpib.conf to enable the alternate behaviour? >> >> For my application, autodiscovery would be very useful. >> >> Regards, >> >> Dirk >> >> _______________________________________________ >> Linux-gpib-general mailing list >> [email protected] >> https://lists.sourceforge.net/lists/listinfo/linux-gpib-general > > _______________________________________________ > Linux-gpib-general mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/linux-gpib-general -- Frank