Re: [foxboro] RV: Open loop alarm

Re: I wouldn't think it would be too hard to get readback in 
any AOUT module.  I thought they all monitored their output current to 
ensure the proper control signal was getting to the field device.

Nope.

The earlier output FBMs ran "open loop" once the D/A converter had its
value. There was nothing for the AOUT to read back other than the register
used by the D/A converter.

The new FBMs actually have a read back circuit that measures the output and
the AOUT blocks can read it.


Regards,
 
Alex Johnson
Invensys Systems, Inc.
10707 Haddington
Houston, TX 77063
+1 713 722 2859 (voice)
+1 713 932 0222 (fax)
+1 713 722 2700 (switchboard)
alex.johnson@xxxxxxxxxxxxxxxx
 

-----Original Message-----
From: foxboro-bounce@xxxxxxxxxxxxx [mailto:foxboro-bounce@xxxxxxxxxxxxx] On
Behalf Of Corey R Clingo
Sent: Sunday, November 27, 2005 8:36 AM
To: foxboro@xxxxxxxxxxxxx
Subject: Re: [foxboro] RV: Open loop alarm

.My definition here is pretty simple -- loss of continuity/high resistance 
between the + and - terminals on the output channel.

In truth, I figured Alex was talking about inputs, and maybe should have 
asked that question earlier.  But the original gentleman's question was 
about outputs, and I was somewhat shocked to learn that there was 
something I had had an issue with in the system from (my) day one and 
either a) I just didn't know how to fix it all this time, or b) the 
Foxboro Director of System Architecture didn't know it was an issue, and 
therefore it would likely remain so.


As a side note, I wouldn't think it would be too hard to get readback in 
any AOUT module.  I thought they all monitored their output current to 
insure the proper control signal was getting to the field device.


Corey Clingo
BASF Corp.






"Joseph M. Riccardi" <Joe@xxxxxxxxxxxxx> 
Sent by: foxboro-bounce@xxxxxxxxxxxxx
11/26/2005 12:45 PM
Please respond to
foxboro@xxxxxxxxxxxxx


To
<foxboro@xxxxxxxxxxxxx>
cc

Subject
Re: [foxboro] RV: Open loop alarm







I think Corey needs to clarify how he defines "open loop".  I believe 
there
may be some confusion ...

Joseph M. Riccardi
DCS Services - Industrial Process Controls

www.eRiccardi.com

Joe@xxxxxxxxxxxxx
"To give real service you must add something that cannot be bought or
measured with money; and that is sincerity and integrity." - Donald A. 
Adams

-----Original Message-----
From: foxboro-bounce@xxxxxxxxxxxxx [mailto:foxboro-bounce@xxxxxxxxxxxxx] 
On
Behalf Of Johnson, Alex P (IPS)
Sent: Saturday, November 26, 2005 1:10 PM
To: foxboro@xxxxxxxxxxxxx
Subject: Re: [foxboro] RV: Open loop alarm

AOUTs don't have readback in older modules. There are new AOUTs that do.

I thought the question was about AINs.

Regards,

Alex Johnson
Invensys Systems, Inc.
10707 Haddington
Houston, TX 77063
+1 713 722 2859 (voice)
+1 713 932 0222 (fax)
+1 713 722 2700 (switchboard)
alex.johnson@xxxxxxxxxxxxxxxx

-----Original Message-----
From: foxboro-bounce@xxxxxxxxxxxxx [mailto:foxboro-bounce@xxxxxxxxxxxxx] 
On
Behalf Of Corey R Clingo
Sent: Saturday, November 26, 2005 12:07 PM
To: foxboro@xxxxxxxxxxxxx
Subject: Re: [foxboro] RV: Open loop alarm

Well, I must have a day zero system (no pun intended :).  Or maybe you can
help me out here.  I built an AOUT block to point #8 on a FBM04 with no
wires on it.  I set BAD=1, IOMOPT=1, SCO=3.  I put the block in AUTO and
manipulated the MEAS.  It was faithfully conditioned and passed through to
OUT; no alarms were generated, and INITO was 0.  Is there anything else 
one
has to do to get it to alarm and/or initialize on open loop?

I'll try it on a FBM237 next week when we get one hooked up.


Corey Clingo
BASF Corp.





"Johnson, Alex P (IPS)" <alex.johnson@xxxxxxxxxxxxxxxx> Sent by:
foxboro-bounce@xxxxxxxxxxxxx
11/26/2005 11:14 AM
Please respond to
foxboro@xxxxxxxxxxxxx


To
foxboro@xxxxxxxxxxxxx
cc

Subject
Re: [foxboro] RV: Open loop alarm






If you set the SCI to the proper value (4-20ma) and set the BAD option,
you
get the described behavior for 4-20ma signals. This has been true since
day
one.

Regards,

Alex Johnson
Invensys Systems, Inc.
10707 Haddington
Houston, TX 77063
+1 713 722 2859 (voice)
+1 713 932 0222 (fax)
+1 713 722 2700 (switchboard)
alex.johnson@xxxxxxxxxxxxxxxx


-----Original Message-----
From: foxboro-bounce@xxxxxxxxxxxxx [mailto:foxboro-bounce@xxxxxxxxxxxxx]
On
Behalf Of Corey R Clingo
Sent: Saturday, November 26, 2005 10:24 AM
To: foxboro@xxxxxxxxxxxxx
Subject: Re: [foxboro] RV: Open loop alarm

On which version of I/A does this happen?  Open loops on analog outputs
are not detected on any version I've used up to 7.1/CP60, even with the
BAD option set, on legacy or 200-series FBMs.  I remember being quite
surprised at this, as it is a standard feature on the Honeywell AO blocks
I used before coming to I/A.  It would be nice to have.

Corey Clingo
BASF corp.









_______________________________________________________________________
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:             http://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:             http://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:             http://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:             http://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:             http://www.freelists.org/list/foxboro
to subscribe:         mailto:foxboro-request@xxxxxxxxxxxxx?subject=join
to unsubscribe:      mailto:foxboro-request@xxxxxxxxxxxxx?subject=leave

Other related posts: