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HP-IL protocol questions
12-27-2019, 07:33 PM
Post: #4
RE: HP-IL protocol questions
(12-27-2019 05:50 PM)J-F Garnier Wrote:  A more complete list is detailed in appendix C.4 of the HP-IL specification (available on MoHPC DVD/USB-key), including the "Analytic Instrument" class (112-127) and the definition of the subclasses.

Thanks for that. I'm not sure if I'm looking at the right document, I see "Accessory ID and Status Message Definitions" in appendix D of the "HP-IL Reference Specification."

(12-27-2019 05:50 PM)J-F Garnier Wrote:  Regarding the HP-IL ID and AID, not all HP devices comply to these rules, for instance the HP3468 multimeter doesn't answer at all to the SAI (returns the SAI unchanged), it must be searched by its ID="HP3468A" or "HP3468B" depending on the multimeter version! It was a true design flaw in my opinion.
And on the other hand, the HP-82161 cassette drive, the HP82162 printer, and maybe others don't answer to the SDI command, but just to the SAI.

Yuck! Given that the 41's and 71's HP-IL modules include functions designed to work on both AID and ID you'd think HP would make devices that actually fit in with this!

(12-27-2019 05:50 PM)J-F Garnier Wrote:  
Quote:Question 2: [...] Does it send another ETO/ETE frame [...] or does it just forward the SDA frame back to the controller?

Devices generally are sending an EOT in response to a SDA if they have no (or no more) data to send, this is my recommendation for HP-IL device implementation.

Yup. That makes sense and it's what I actually implemented while hoping to get an answer here.

(12-27-2019 05:50 PM)J-F Garnier Wrote:  But some HP devices (the HP-82166 and the HP82164 interfaces) can just hold the SDA until they get something to send from the interface side. Of course, this locks the loop, potentially forever if no data is received from the interface side.

Now, that is is just nasty!

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Messages In This Thread
HP-IL protocol questions - grsbanks - 12-27-2019, 01:03 PM
RE: HP-IL protocol questions - grsbanks - 12-27-2019, 01:27 PM
RE: HP-IL protocol questions - J-F Garnier - 12-27-2019, 05:50 PM
RE: HP-IL protocol questions - grsbanks - 12-27-2019 07:33 PM
RE: HP-IL protocol questions - J-F Garnier - 12-27-2019, 08:38 PM
RE: HP-IL protocol questions - grsbanks - 12-27-2019, 09:21 PM

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