Re: [foxboro] Ladder Logic
- From: tjvandew@xxxxxxxxx
- To: foxboro@xxxxxxxxxxxxx
- Date: Tue, 15 May 2012 11:10:19 +0000
Jeremy,
You are right about only being able to set an OFL from one rung and about
the size of the ladder, but we recompiled ladder logic routinely with no bumps
to the process. We considered that a strength compared to recompiling HLBL
sequence code where things could get squirrely. The execution speed of the
ladder was the other strength. CIN's and CO's are processed in 3-5ms but
bringing in IFL's or passing out to external parameters like OFL's still
happens at the PLB block processing cycle. If you need first out functionality
for CIN's connected to an FBM the PLB can do it with a "trip trap". But if you
need larger scale PLC capability using a real PLC is still a better solution.
Cheers,
Tom
Sent from my Verizon Wireless BlackBerry
-----Original Message-----
From: Jeremy Milum <jmilum@xxxxxxxxx>
Sender: foxboro-bounce@xxxxxxxxxxxxx
Date: Mon, 14 May 2012 08:50:24
To: foxboro@xxxxxxxxxxxxx<foxboro@xxxxxxxxxxxxx>
Reply-To: foxboro@xxxxxxxxxxxxx
Subject: Re: [foxboro] Ladder Logic
On Tuesday, May 1, 2012, DUNHAM, KENNETH J wrote:
> Curious to know what limitations you are referring to?
>
It's been a long time since I used PLBs, so I could be wrong on some of
these, but here is what I recall as some of the things that bothered me at
the time
* 100 rungs total per FBM
* only able to set a particular OFL from a single rung
* have to compile everything if editing a single rung, thus the process
must be down to make changes
--
--
Jeremy Milum
_______________________________________________________________________
This mailing list is neither sponsored nor endorsed by Invensys Process
Systems (formerly The Foxboro Company). Use the info you obtain here at
your own risks. Read http://www.thecassandraproject.org/disclaimer.html
foxboro mailing list: //www.freelists.org/list/foxboro
to subscribe: mailto:foxboro-request@xxxxxxxxxxxxx?subject=join
to unsubscribe: mailto:foxboro-request@xxxxxxxxxxxxx?subject=leave
_______________________________________________________________________
This mailing list is neither sponsored nor endorsed by Invensys Process
Systems (formerly The Foxboro Company). Use the info you obtain here at
your own risks. Read http://www.thecassandraproject.org/disclaimer.html
foxboro mailing list: //www.freelists.org/list/foxboro
to subscribe: mailto:foxboro-request@xxxxxxxxxxxxx?subject=join
to unsubscribe: mailto:foxboro-request@xxxxxxxxxxxxx?subject=leave
Other related posts:
