Re: [foxboro] Word-Swaping on Modbus Interface Micro I/A (32-bit IEEE-Floating Point)

Look at document B0400FK, section 5.  Table 5-5 (page 44) shows that you
can swap bytes, even across words.  Hopefully this helps.  I'm not familiar
with FRIN blocks.


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 08:52:34 AM:

> Steve,
>
> thanks, but my Real value is 32-bit IEEE-754 Floating Point format, lik=
> e
> this:
>
>
>
> Decimal Value Entered: 12.34
>
>
> Single precision (32 bits):
>
>
> Binary:=A0=A0=A0=A0=A0Status: normal
> |-------------+--------------------------------------------------------=
> --+------------------------------------------------|
> |             |                                                        =
>   |                                                |
> |    Bit 31   |                                                        =
>   |                                                |
> |   Sign Bit  |                       Bits 30 - 23                     =
>   |                   Bits 22 - 0                  |
> |      0      |                      Exponent Field                    =
>   |                   Significand                  |
> |     0: +    |                         10000010                       =
>   |           1 .10001010111000010100100           |
> |     1: -    |       Decimal value of exponent field and exponent     =
>   |        Decimal value of the significand        |
> |             |                       130 - 127 =3D 3                  =
>     |                    1.5425000                   |
> |             |                                                        =
>   |                                                |
> |             |                                                        =
>   |                                                |
> |-------------+--------------------------------------------------------=
> --+------------------------------------------------|
>
>
>
>
> Hexadecimal: 414570A4=A0=A0Decimal: 12.340000
>
>
>
> The FRIN Block read it in the right way, if the Modbus-Words are in the=
>
> right order. But it isn't in my case.
>
> 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
>
>
> |---------+---------------------------->
> |         |           steve.shimp@exxon|
> |         |           mobil.com        |
> |         |           Sent by:         |
> |         |           foxboro-bounce@fr|
> |         |           eelists.org      |
> |         |                            |
> |         |                            |
> |         |           14.02.2006 14:21 |
> |         |           Please respond to|
> |         |           foxboro          |
> |         |                            |
> |---------+---------------------------->
>   >--------------------------------------------------------------------=
> -----------------------------------------------------------------------=
> -------|
>   |                                                                    =
>                                                                        =
>        |
>   |       To:       foxboro@xxxxxxxxxxxxx                              =
>                                                                        =
>        |
>   |       cc:                                                          =
>                                                                        =
>        |
>   |       bcc:                                                         =
>                                                                        =
>        |
>   |       Subject:  Re: [foxboro] Word-Swaping on Modbus Interface Micr=
> o I/A                                                                  =
>        |
>   >--------------------------------------------------------------------=
> -----------------------------------------------------------------------=
> -------|
>
>
>
>
> Rolf,
>
> We have done this with RIN blocks on a Modbus interface.  The "trick" i=
> s 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 tha=
> t 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 fir=
> st
> word is pulled into a RIN block that has an MGAIN value of 0 (zero).  T=
> he
> 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 fo=
> r
> 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 O=
> rder
> > of the Modbus Adresses to 47201 and 407200 (Value Hex 4145 70A4) on t=
> he
> > 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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>
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>
>
>
>
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