S5 Analog Scale problem!!

I need some help to understand this S5 code:



AN F 16.3

JC =M001

L IW 60

SRW 3

L KH 0FFF

AW

FDG

L KG 780

-G

L KG 0.312

/G

T SD 636

L KG 0

>G

JC =M001

L KG 0

T SD 636

M001: ***



What I do know:

Signal: 4- 20mA

Range: 0-5000 hPa

I/O moudel: 1794-IE8 (12 bit on Profibus)

IF F16.3=1 then I/O signal is Ok and the value are calculated to SD 636

IF SD 636 < 0 then SD 636 = 0



My problem is that can’t understand KG 780 and KG 0.312



I can’t replay any questions to day, but I will be back tomorrow.

glasdam said:

I need some help to understand this S5 code:



AN F 16.3

JC =M001

L IW 60

SRW 3

L KH 0FFF

AW

FDG

L KG 780

-G

L KG 0.312

/G

T SD 636

L KG 0

>G

JC =M001

L KG 0

T SD 636

M001: ***



What I do know:

Signal: 4- 20mA

Range: 0-5000 hPa

I/O moudel: 1794-IE8 (12 bit on Profibus)

IF F16.3=1 then I/O signal is Ok and the value are calculated to SD 636

IF SD 636 < 0 then SD 636 = 0



My problem is that can’t understand KG 780 and KG 0.312



I can’t replay any questions to day, but I will be back tomorrow.

Click to expand...

This must be a S5-135U. KG is the format used to display floating point numbers

As curlyandshemp says, KG = Floating point, the FDG instruction converted the input from integer to floating point.

The programmer did the analog conditioning a long winded way as well. What he did as


would normally be done quicker as


that is the most commonly used method to remove the unwanted bits.

Thanks for your answer




However this do not solve the main part of my problem the scaling part:
(IW60– KG 780)/ KG 0.312 ; (IW60 modified as you described)

It looks like he's subtracting the 4ma first then scaling between 0-1000