PMP Mail Archive: RE: PMP> The Input Switching Group

PMP Mail Archive: RE: PMP> The Input Switching Group

RE: PMP> The Input Switching Group

Bob Pentecost (bpenteco@boi.hp.com)
Thu, 13 Feb 1997 15:51:27 -0700

I've rewritten the objects as follows:

-- The Input Switching Group

--
-- The input switching group allows the administrator to set the
-- input subunit timeout for the printer and to control the automatic
-- input subunit switching by the printer when an input subunit becomes
-- empty.
--
-- This group is optional. However, to claim conformance to this group,
-- it is required to implement every object in the group.

prtInputMediaLoadTimeout OBJECT-TYPE SYNTAX Integer32 MAX-ACCESS read-write MIN-ACCESS read-only STATUS current DESCRIPTION "When the printer is not able to print due to a subunit being empty or the requested media must be manually loaded, the printer will wait for the duration (in seconds) specified by this object. Upon expiration of the timeout, the printer will take the action specified by prtInputNextIndex.

The event which causes the printer to enter the waiting state is product specific. If the printer is not waiting for manually fed media, it may switch from an empty subunit to a different subunit without waiting for the timeout to expire.

A value of (-1) implies 'other' or 'infinite' which translates to 'wait forever'. The action which causes printing to continue is product specific. A value of (-2) implies 'unknown'." ::= { prtInputEntry 24 }

prtInputNextIndex OBJECT-TYPE SYNTAX Integer32 MAX-ACCESS read-write MIN-ACCESS read-only STATUS current DESCRIPTION "The value of prtInputIndex corresponding to the input subunit which will be used when this input subunit is emptied and the timeout specified by prtInputMediaLoadTimeout expires. A value of zero(0) indicates that auto input switching will not occur when this input subunit is emptied. If the timeout specified by prtInputLoadMediaTimeout expires and this value is zero(0), the job will be aborted." ::= { prtInputEntry 26 }

I changed prtInputMediaLoadTimeout so that it just describes the timeout, when the timeout applies and what causes printing to continue when the timeout is infinite. prtInputNextIndex specifies what happens when the timeout expires. My original changes can be still be found at ftp://ftp.pwg.org/pub/pwg/pmp/contributions/inputsw.doc while this round of changes are at ftp://ftp.pwg.org/pub/pwg/pmp/contributions/inputsw2.doc (both Word documents with revision marks).

Hopefully, this gets us closer to the correct wording. What do you think?

Bob Pentecost HP

---------- From: Caruso,Angelo[SMTP:Angelo_Caruso@wb.xerox.com] Sent: Thursday, February 13, 1997 11:17 AM To: Bob Pentecost; "pmp@pwg.org" Cc: "'Smith, Brad'" Subject: RE: PMP> The Input Switching Group

Bob,

I agree with you 100% regarding your description of how things actually work. But, I think that relying on the sentence "The event which causes the printer to enter the waiting state is product specific" will lead to confusion later. The descriptions for the objects as they current stand apply to the manual feed case as you described it. But, they totally contradict the behavior for the normal paper trays. I think they need to be re-written to describe the normal paper tray behavior, with a couple of extra sentences that describe the exceptional behavior for the manual feed case.

Angelo

---------- From: Bob Pentecost To: "pmp@pwg.org"; "'Caruso,Angelo'" Cc: "'Smith, Brad'" Subject: RE: PMP> The Input Switching Group Date: Wednesday, February 12, 1997 4:31PM

Angelo,

After talking to someone today about the objects in the Input Switching Group, I reread your mail and think I know where our confusion is coming from.

You wrote: > The only issue I have left is that in my experience we would > apply prtInputNextIndex first when the tray goes empty. Then, if it's > value is zero, we would apply prtInputMediaLoadTimeout. According to > the current description for the timeout it's the other way round -- > timeout first, then switch. This does not make sense to me.

HP printers automatically switch to a new tray if it has the same media as a tray that empties. We would apply the timeout only in the case that there is not matching media anywhere in the printer.

This object originated with manual feed requests, its intention was to wait for the manual feed and then switch to another tray when the timeout expires. Your preference to switch first, then timeout doesn't allow time to complete the manual feed request. However, for the case of running out of media in a tray, I agree that you'd want to switch right away.

I think both of our implementations would be legal because prtInputMediaLoadTimeout specifies "The event which causes the printer to enter the waiting state is product specific."

If a user specifies prtInputNextIndex = 0, then the timeout should be -1 unless they want the job to abort when prtInputMediaLoadTimeout expires.

I have changed the objects in the Input Switching Group and upload a Word file with the revisions marked. You can find it at ftp://ftp.pwg.org/pub/pwg/pmp/contributions/inputsw.doc.

Let me know what you think.

Bob Pentecost HP

---------- From: Caruso,Angelo[SMTP:Angelo_Caruso@wb.xerox.com] Sent: Monday, January 27, 1997 5:21 PM To: pmp@pwg.org Subject: RE: PMP> The Input Switching Group

Bob,

I agree, there are too many objects. I think we both agree on the objects we need to keep (though I may have confused you with my previous message on this subject). To summarize, I think we need to keep

prtInputMediaLoadTimeout and prtInputNextIndex.

And, we should remove prtInputAutoSwitch.

This will require that we wordsmith the descriptions for the objects we keep. The only issue I have left is that in my experience we would apply prtInputNextIndex first when the tray goes empty. Then, if it's value is zero, we would apply prtInputMediaLoadTimeout. According to the current description for the timeout it's the other way round -- timeout first, then switch. This does not make sense to me.

I think we need people to respond with their implementation experience. Do most printers check to see if they should autoswitch first, then apply the timeout? Or do most printers timeout first, then decide if they should autoswitch?

Any other opinions?

Thanks, Angelo

---------- From: pmp-owner@pwg.org To: "'Caruso,Angelo'" Cc: Bob Pentecost; "pmp@pwg.org" Subject: RE: PMP> The Input Switching Group Date: Thursday, January 23, 1997 5:31PM

Angelo,

Looking at the definitions of prtInputManualFeedTimeout (which is supposed to be prtInputMediaLoadTimeout), prtInputAutoSwitch and your new definition of prtInputNextIndex, it looks like we've got too many controls for what we need to do.

The objective is to have a timeout when the needed media is not available. The timeout requirement is satisfied by prtInputMediaLoadTimeout. The action to be taken can be controlled by prtInputNextIndex, as you've defined it if you change the wording to "A value of zero(0) indicates that auto input switching will not occur and the job will be aborted when this input subunit is emptied." I don't see the need for prtInputAutoSwitch to control switching, when prtInputNextIndex can determine the action to be taken.

You claim that prtInputNextIndex is not necessary, but you don't explain why. I see that it is needed for the printers that wish to allow the next input subunit to be configurable. For HP printers, we would support only values of zero and -2 since we don't know which tray we will switch to until the load media request is generated.

When we discussed this at the meeting on Friday afternoon, I didn't realize that there were multiple controls. This looks like a case where we can do some simplification, but let's not delete the wrong object.

Let me know if I'm missing something.

Bob Pentecost HP

prtInputManualFeedTimeout OBJECT-TYPE SYNTAX Integer32 MAX-ACCESS read-write MIN-ACCESS read-only STATUS current DESCRIPTION "The duration (in seconds) after which the printer shall either:

(a) switch to another input subunit, if the value of prtInputNextIndex is non-zero and prtInputAutoSwitch is on(3) or (b) abort any job waiting for manually fed input, if the value of prtInputNextIndex is zero or prtInputAutoSwitch is off(4) or notPresent(5).

The event which causes the printer to enter the waiting state is product specific. A value of (-1) implies 'other' or 'infinite' which translates to 'this input subunit doesn't support manual feed'. A value of (-2) implies 'unknown'." ::= { prtInputEntry 24 }

prtInputAutoSwitch OBJECT-TYPE SYNTAX PresentOnOff MAX-ACCESS read-write MIN-ACCESS read-only STATUS current DESCRIPTION "Indicates the state of the auto input switching feature. The value notPresent(5) indicates the feature is not currently supported. Exact behavior of this feature is product specific." ::= { prtInputEntry 25 }

---------- From: Caruso,Angelo[SMTP:Angelo_Caruso@wb.xerox.com] Sent: Monday, January 13, 1997 5:19 PM To: pmp@pwg.org Subject: PMP> The Input Switching Group

One of my action items from the Albuquerque meeting is to refine and justify the new objects in the Input Switching Group. Here is my first crack at refining these objects:

prtInputNextIndex OBJECT-TYPE SYNTAX Integer32 MAX-ACCESS read-write MIN-ACCESS read-only STATUS current DESCRIPTION "The value of prtInputIndex corresponding to the input subunit which will be used when this input subunit is emptied. A value of zero(0) indicates that auto input switching will not occur when this input subunit is emptied. A value of (-1) means other. The value (-2) means 'unknown' and specifically indicates that an implementation specific method will determine the next input subunit to use at the time this subunit is emptied. The value (-3) means input switching is not supported for this subunit."

Based on the new description above, I am once again of the opinion that the prtInputAutoSwicth object is uneccessary. Did I forget anything from the discussion Friday afternoon? Any other comments?

Thanks, Angelo