Re: [foxboro] Word-Swaping on Modbus Interface Micro I/A

There are ways to swap the order of bits (low-order vs. high-order) by
setting some block parameters, but there isn't a way to swap "words" from
what I know.

Steve Shimp
Maintenance & Systems Engineer
ExxonMobil Paulsboro Lube Plant
phone: 856.224.5059      cell: 609.820.8501      fax: 856.224.5030
email:  steve.shimp@xxxxxxxxxxxxxx

foxboro-bounce@xxxxxxxxxxxxx wrote on 02/14/2006 08:37:26 AM:

> I recall a similar situation with regards to swapped order on bits
through
> the FMCIN and FMCOUT blocks.
> This happened in 1999 so please excuse me if it seems a bit fuzzy...
> My subconscious reminds me that I had solved the inversion issue by
setting
> the MULTWR parameter of the ECB109 to 0...(I had previously set it to 1)
> Unfortunately, I do not recall the exact implication of this change other
> than that it actually solved it for me.
> This of course is much less defined and documented as Steve's solution.
>
> Howard
> -----Original Message-----
> From: foxboro-bounce@xxxxxxxxxxxxx [mailto:foxboro-bounce@xxxxxxxxxxxxx]
On
> Behalf Of steve.shimp@xxxxxxxxxxxxxx
> Sent: Tuesday, February 14, 2006 8:21 AM
> To: foxboro@xxxxxxxxxxxxx
> Subject: Re: [foxboro] Word-Swaping on Modbus Interface Micro I/A
>
> Rolf,
>
> We have done this with RIN blocks on a Modbus interface.  The "trick" is
to
> use 2 separate RIN blocks for each 16-bit word.  Then use a CALC block to
> manipulate the two values from the RIN blocks to determine the original
> value.
>
> For example, there is a value transmitted over the Modbus interface that
is
> 67098.2 originally.  The words are transmitted such that the first word
is
> the low order bits and the second word is the high order bits.  The first
> word is pulled into a RIN block that has an MGAIN value of 0 (zero).  The
> second word is pulled into a RIN block that has a MGAIN value of 1000
> (based upon the documentation of the Modbus sending device and how the
> interface is designed).  The RIN blocks are therefore "reading" 98.2 for
> the low order and 67000 for the high order.  Pull these RIN blocks into a
> CALC block and simply add them together.
>
> Hope this helps.
>
>
> Steve Shimp
> Maintenance & Systems Engineer
> ExxonMobil Paulsboro Lube Plant
> phone: 856.224.5059      cell: 609.820.8501      fax: 856.224.5030
> email:  steve.shimp@xxxxxxxxxxxxxx
>
> foxboro-bounce@xxxxxxxxxxxxx wrote on 02/14/2006 08:00:55 AM:
>
> >
> > Hi List,
> >
> > our I/A-System is Unix V6.4 and Micro I/A V6.2.5 with 2 Modbus serial
> > Interfaces attached. I would like to read/write data from/to a Modbus
> > Device (Brabender weighing unit) with FRIN /FROUT blocks. But the two
> 16bit
> > Modbus Words for a real value are in wrong order.  Example: Value 12.34
> in
> > the Modbus Adresses 47200 and 47201 (Value Hex 70A4 4145) will be
> displayed
> > on FoxView as 4017238209...................... How can I change the
Order
> > of the Modbus Adresses to 47201 and 407200 (Value Hex 4145 70A4) on the
> > I/A-System? There is no way to change it on the Modbus Device!
> >
> > Thanks for helping,
> >
> > Regards
> >
> > Rolf Reber
> > ____________________________________
> > EMS-CHEMIE AG
> > Business Unit EMS-SERVICES
> > Abt. Anlagenbau / Prozessleitsysteme
> > Reichenauerstrasse
> > CH-7013 Domat/Ems
> >
> > Phone: +41 (0) 81 / 632 71 49
> > Fax:      +41 (0) 81 / 632 74 04
> > mailto: rolf.reber@xxxxxxxxxxxxxx
> > http://www.emsservices.ch

 
 
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