Re: [foxboro] CALC vs. IND question
- From: "Michael Kessler" <mkessler@xxxxxxxxxxxx>
- To: <foxboro@xxxxxxxxxxxxx>
- Date: Thu, 27 Mar 2008 11:01:19 -0400
Mike,
You can insert comments on a step for CALC's by preceding the comment with a
semi-colon. Comment space is limited, but better than nothing.
Make sure all your existing mathematical operations are supported by
sequence blocks. For example, I've learned that exponents are difficult to
do in a sequence block.
Michael Kessler,
KIC Inc.
> -----Original Message-----
> From: foxboro-bounce@xxxxxxxxxxxxx
> [mailto:foxboro-bounce@xxxxxxxxxxxxx]On Behalf Of
> Mike_Adams@xxxxxxxxxxxxx
> Sent: Wednesday, March 26, 2008 5:45 PM
> To: foxboro@xxxxxxxxxxxxx
> Subject: [foxboro] CALC vs. IND question
>
>
> Hello list,
>
> I have some existing compounds in 4 I/A nodes that each have about 20 CALC
> blocks running at a 2 sec period with pretty good phasing. These blocks
> are running somewhat arcane mathematical calculations with 15 to 25 steps
> each but only 2 or 3 real outputs are generated per CALC block.
>
> The CALC steps are not commented at all. We are running into problems
> where it is becoming harder to keep up with what is going on in
> these CALCs
> and it is very hard to edit them efficiently. I am interested in
> replacing
> these CALCs with IND blocks that would do the same work but be much easier
> to troubleshoot, document & edit.
>
> I know that INDs load the system more than CALCs but I'm not sure by what
> degree. All 4 control processors involved are CP30s. Two of
> these CPs are
> lightly loaded but the other 2 are heavily loaded.
>
> If I configured an IND to run at the same period as a CALC and do the same
> calculations, what would a reasonable guesstimate of the increase in load
> be? I just want to get a rough idea on a 1:1 comparison for starters.
>
> I realize I can probably do the following to ease the load increase
> incurred by going to INDs:
>
> - lengthen the period to 5 sec & phase them well
> - put 2 or 3 CALC blocks worth of steps into 1 IND
> - place strategic WAIT statements in the IND code
>
> Thanks in advance,
>
> Mike Adams
> Mitsubishi Polyester Film, LLC
> Greer, SC USA
> 864-879-5231
>
>
>
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