Re: [foxboro] ACCUM Block With Period = 8 (1 Hour)

Tom,  I have V8.3 and will give a try.  What phase are you using?
Chris


On 10/29/09, Tom Badura <tbadura@xxxxxxxxxxx> wrote:
>
> David,
> Thanks for the test and response.  And thanks to everyone else who
> responded.
> 1.)  This is a ZCP270 at Ver. 8.3.
> 2.)  The ACCUM Input Limits are LSCI = [-2000], HSCI = 100000
>     Output Limits are LSCO = 0 HSCO = 9999999
>
> The MEAS input is connected to a CALCA RO01 with the CALCA block in manual
> and RO01 = 1000.    I ran the ACCUM over the night for 16 hours and had an
> ACCUM output = 1436.4 which is the same 89.8 / hour that I saw before.  The
> blocks calculated MRATE = 0.27778 / sec which looks correct.
>
> To verify I haven't fat fingered anything else, I took the exact same ACCUM
> block and just changed the period to 7 (10 mins.).  I left everything else
> the same.  The block output now increments by 1000 every 10 minutes as
> expected. The calculated MRATE is 1.6667 / sec. which again looks correct.
>
> I also built a second ACCUM with your config - AIN block 60 GPH.  After 1
> hour this block incremented to an OUT = 5.4 - off by the same factor
> (11.11)
> as my other block.  The MRATE = 0.01667 / sec.
>
> The reason I keep mentioning the MRATE is that I think the ACCUM block may
> do something internally to compensate for actual elapsed time since the
> last
> increment.  When I configured a faster period (10 secs for instance), I
> would see output values of 1000, 2001, 2999, 3000., 3998, 5000, etc.  This
> makes me think there may be more going on than the straight OUT = OUT +
> (MEAS * MTRFAC), and may explain why a change in period could affect the
> calculation.  Just a guess on my part.
>
> Anyone out there with a ZCP270 at V8.3 that would like to give this a try?
>
> * Please forgive multiple posts of this message if you receive them.  I
> have
> been trying to respond for a while and nothing seems to get posted.  Trying
> again from home.
> (banned for too many foolish posts?)
>
> Tom Badura
> Plastics Engineering Company
> tbadura@xxxxxxxxxx
>
>
> -----Original Message-----
>
> Tom,
>
> We ran the test on an ACCUM here
> Period  = 8
> Phase   = 1
> Pcntop = 0
> Mtrfac  = 1
>
> We tied an AIN block with 60 GPH into the MEAS of the ACCUM.  At the end of
> 1 hour we had 60 (as expected).
> This was in an FCP270 at I/A 8.2
>
> So the questions are
> 1) is this in a Integrator/Gateway instead of a straight CP.  The periods
> in
> Integrators are different than a regular CP.
> 2) Do you have some kind of hi limit on the ACCUM block that was being
> violated.
> Let me know as I would like to know if there is something (else) out there
> that I need to lookout for.
>
> Thanks,
>
> David
>
>
>
>
>
>
>
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