[foxboro] Phasing that causes intermittent alarming?
- From: Jalen Ong <jalen.ong@xxxxxxxxx>
- To: foxboro@xxxxxxxxxxxxx
- Date: Mon, 14 Nov 2011 21:51:00 +0800
Dear Joseph,
BPC is 0.5 sec.
Dear Kevin,
Thanks for the explanation. If I get you correctly, the block will run once
on new data and a 2nd time on
old data. So the old data would be the same as the previous new data right.
Meaning, we should not expect any change in reading during the 2nd time on
old data? Thanks.
Cheers,
Jalen
> Subject: Re: [foxboro] foxboro Digest V11 #364
> Date: Wed, 9 Nov 2011 07:41:51 -0600
> From: "Riccardi, Joseph" <Joseph.Riccardi@xxxxxxxxxxx>
>
> What is your Gateway BPC; 1 sec? If 1 sec, Period 4, your valid Phases
> are only 0-3...
>
> Joseph M. Riccardi
> Senior I&C Engineer
> Bechtel Parsons Blue Grass Team
> Richmond, KY
> 859-626-4368 <859-626-4368>
>
>
> ------------------------------
>
> Date: Thu, 10 Nov 2011 09:11:37 +0800
> Subject: Re: [foxboro] Phasing change for compound in gateway
> From: Kevin Fitzgerrell <fitzgerrell@xxxxxxxxx>
>
> Jalen,
> An I/O block (or other block type) can be on a different period/phase than
> the MDSCAN block. The data defined in a compound's MDSCAN block is
scanned
> to/from the ECB16 (assuming Modbus INT30) input buffer. I/O blocks in a
> compound access that data in the ECB16. If a block is on per/phase 3/3
and
> the MDSCAN is 4/7, the block will run once on new data and a 2nd time on
> old data.
>
> A bigger issue may be changing the MDSCAN block itself. If I remember
> correctly, changing the MDSCAN period/phase does result in one scan of
> "smurfed" data while the block/scan initializes.
>
> Don't change the period/phase of your compound to match the new blocks
> until all the blocks within are at their new period/phase. Depending on
> block period/phases you may want to change your compound's period/phase to
> 0/0 initially and then change back after finishing the edits.
>
> I normally use iccdrvr.tsk to change all block period/phases rather than
> ICC so that the change-over goes faster than the one block at a time you
> can do in ICC, and normally have a roll-back script ready just in case.
>
> Regards,
>
> Kevin
--
Best regards,
Jalen
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