Experimental Physics and
Industrial Control System

"David Dudley" <[email protected]> · Wed, 04 Apr 2007 11:09:20 -0500

Still no cigar (maybe that should be bubblegum - you know, to be
"politically correct" ;-)

Now, the BO is outputing to a modbus device, I have OMSL=closed_loop
and [email protected].  When the database loads, if I do a 'dbpr 2' on the
record, I can see that DISV does indeed have a 1 value, and DOL is
pointing back to it, however VAL is still zero.  Activating the record
(it's forward linked from another record) causes it to output a zero,
and the VAL still remains zero.

David Dudley

>>> "Ned D. Arnold" <[email protected]> 4/4/2007 10:13 AM >>>
David -

I seem to remember (when I actually worked with this stuff) that
setting the DOL to 1 only worked for Soft Channel BOs.  Try setting DOL
to a link that is always one (e.g. DISV or DISA of the same BO record)
and OMSL to closed_loop.  This way it will always fetch a 1 for the
output.  This eliminates the need for the extra BI record you
described.

Ned

David Dudley wrote: Unfortunately, that didn't work.In vdct, I can set
the .VAL field to 1, but when I load the db, the VALfield is 0.  Setting
DOL to 1 causes it to have a 'CONSTANT 1' valuewhen you do a 'dbpr' on
the field, and I have OMSL set to 'closed-loop',however the .VAL field
remains at 0.  If I do a forward link to theblock, it outputs a zero,
and the .VAL remains 0.  If a do a 'dbpf' toset the value to 1, it then
works fine.  What I did as a patch aroundthe questionable action was to
use a BI block with its DTYPE set to'Soft Channel' and an INP of '1'
that is linked to the BO, but seemslike a round-about way of doing such
a simple thing.I thought I was probably just missing something on the BO
block.David Dudley  "Paul Sichta" <[email protected]> 4/4/2007 9:20 AM
>>>        David,Can you set the DOL to '1' and use closed-loop control,
rather thanthedefault supervisory. 
BEGIN:VCARDVERSION:2.1X-GWTYPE:USERFN:David
DudleyTEL;WORK:880-3740ORG:;MISTEL;PREF;FAX:880-3741EMAIL;WORK;PREF;NGW:[email protected]:Dudley;DavidEND:VCARD

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System