[Info-vax] Timeout in a write using QUIW.

[Jan-Erik Söderholm]

Den 2023-06-22 kl. 13:25, skrev Phil Howell:
> On Thursday, 22 June 2023 at 7:36:54 am UTC+10, Jan-Erik Söderholm wrote:
>> Den 2023-06-21 kl. 23:25, skrev Stephen Hoffman:
>>> On 2023-06-21 20:45:12 +0000, Jan-Erik S derholm said:
>>>
>>>> Now, here is a technical one...
>>>>
>>>> When doing a *read* from a terminal device using QIOW, one
>>>> can use IO$M_TIMED and supply a timeout value in P3. That
>>>> works perfectly and we use that a lot...
>>>
>>> I've never had great success...
>>
>>
>> I'm sorry about that. As I wrote, it works perfectly. In the
>> case of reads, of course, where it is supported.
>>
>> My question was about writes, and it has been confirmed that
>> timeout paramaters are not supported there. Thanks Arne.
>>
>> Now we need to weight the coding work against getting
>> network cables installed to the printers. Wired printers
>> will also "solve" the issue with the current code. We have
>> 15-20 older similar Zebra label printers, all wired, and
>> we do not see these error scenarios with those.
>> All using the same C routine for the QIOW calls.
>>
>>
>> Jan-Erik.
> While you cannot request a timeout on a WRITEVBLK
> you may be able to workaround this by using READPROMPT
> With this you get two i/o's in one call,
> the first is a write of your "prompt" followed by a read on the same channel.
> If you set up your "prompt" as the content of your label then do the qio call
> it should write this to the device, then do the read, which you can check or ignore.
> If you get a tt_timeout, then wait a bit and retry.
> The most concise explanation of this is in wikipedia on the qio page.
> The I/O user manual just goes on and on
> You may have to increase the size of the typeahead buffer to cater for the size of your label
> as well as managing all the usual qio stuff like buffer lengths, IOSBs, terminator masks, ASTs, etc.
> 
> If I was retiring in a couple of weeks I would recommend cabling up all the printers,
> but it could be an interesting way of getting your successor to hate you?
> 
> Phil
> 
>   

Hi. That was a nice way of "using" (or "mis-using" ? ) QIOW!
I'm actually leaving this place Friday next week, 30 June.

Right now, it seems as we'll simply get the printers hard-wired.
It is 6 printers that are on Wifi now, and our other 15-20 label
printers (all hard-wired) do not show the same error scenario.

Jan-Erik.