issue talking with 2 devices connected via GPIB

[JÞB]

Hmmmm

Sounds like a really old 488 design circa mid 60s-or 70s  The product brochures state a 488 link- (not the current 488.2) so I suspect a "non standard" implementation.

Post a screenshot of the MAX GPIB devices- this will give us a clue how MAX sees the instruments

Post a drawing of the bus - so we are all on the same page

If you can, post a link to the equipment operating manuals- I can't seem to find them online

[markanddave]

Is the 488.2 not backwards compatible?

So the equipment is definitely old. I found a link to one manual and site to get the spec sheet for the other.

Model 1287: http://mm.ece.ubc.ca/mediawiki/images/3/35/1287_manual.pdf

Model 1252A: http://www.solartronanalytical.com/Pages/1252AFRAPage.htm

Attached a screenshot of the MAX after scan for instruments.

Also the GPIB cable has a tag on it that reads:

National Instruments

763507-02 Rev1

Type-X2

Length 2.1meters

2002 10 28

Let me know if I got everything you asked

Thanks

[Dennis_Knutson]

Hard as it is for me to believe, each of those instruments has two separate GPIB addresses according to the manuals. That accounts for for MAX seeing four. They are all, obviously powered on and I cannot account for the problems you are seeing. A call to the vendor might be in order.

[JÞB]

WOW-

OK the dual addressing wasn't too uncommon back in the day.  Especially when the unit was designed to dump to a HP plotter.  I'm not sure you are going to get there using the VISA calls since VISA assumes a "IEEE-488" COMPLIANT interface and this is what I would call a "GPIB style" interface (probably on a interface card developed in-house expressly for the Solaratron equipment.)  Again, this was common back in the day.

Dennis offers good advice!  Time to call the vendor, explain you would like to use their obsolete interface with modern instrument control software, and work closely with their application engineer.

I've been-there-done-that a few times myself.  Its painful but, the equipment manufacturers I've worked with have all been "customer focused" and in every case the manufacturer spun a revision of the interface to bring it into IEEE-488 compliance.

[Albert.Geven]

Hi

In this case I would try each of the four addresses and use the two working addresses.

I have used the solartron with visa for sure and although you have to watch out for timeouts when measuring slowly it should work.

The other instrument I did not use.

[JÞB]

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@Albert Geven wrote:

Hi

In this case I would try each of the four addresses and use the two working addresses.

I have used the solartron with visa for sure and although you have to watch out for timeouts when measuring slowly it should work.

The other instrument I did not use.

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Of course I could be mistaken-  Thanks Albert  The even addresses are the right ones-

unless the 1's address bit is on then the device won't work right.