3.2.1 Responder Packet Timings

[sblair]

*** Warning....this discussion is about to enter Task Group mode ***
Some of the following discussion and details are from earlier drafts. Just because I'm referencing for discussion does not mean they are what is in the FINAL approved standard. In all cases, it is the FINAL standard that is considered law.
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Just had to get that disclaimer out of the way.

Peter, what you've brought up appears to be a valid error. It certainly isn't making sense to me. However, after a stroll down memory lane it has been referencing the same table since it was changed to be a reference rather than a hard # in the text.

I had to dig back in draft versions to an early draft where it was actual hard numbers in the text.

From draft v1.2c on May 11, 2004:

No single Inter-slot delay shall exceed 2.0mS.

Responders may consider controller packets with inter-slot delays of 2.1mS or greater to be lost.

It was after that draft that it was re-worked to point to the Table and Line # instead. Since that point it has always pointed to the "Controller Packet Spacings Table"

My guess at this point would be that it should have pointed to Table 3-3 Line 1.

Draft v1.3 had the following:

Responders may consider controller packets with inter-slot delays exceeding the maximum in line 1 of Table 3-2 to be lost.

Draft v2.1 on Oct 25, 2004 changed it to what it currently is of being "line 3".

When we were editing the v2.1 draft at LDI is when we must have spotted the issue but instead changed the line # rather than the table #. It then passed through two following Public Reviews with no comments.

I would like to get confirmation from more Task Group members here to see if everyone is in agreement the current text is an error and then I'll forward to Karl to find out if/how to issue an Errata.

[-dalc-]

"Responders may consider controller packets with inter-slot delays of 2.1mS or greater to be lost"...

So, every USB/DMX PC interface which outputs packets directly (whithout esternal buffering & retrasmission circuit) may be cause packets to be lost, due the time scheduling of the operating system (for windows tipically >10ms).

In my RDM-responder firmware I set up the inter-slot delay timeout equal to the packet timeout equal to 1S. Is it a valid solution?