scl fb in siemens

hi friends any one please tell me how to use scl function block in siemens s7 1200
my requirement is to convert 4-20 ma current signals to 0 to 120 ppm
i am new to this software

Hello Dilliganesh,

At the first input "IN" put in you analog in value as int.
At "Hi_lim" put in your high limit ( 120)
At "Lo_lim" put in your Low limit(0)

Best Regards /Victor

This is the block i'm talking about if there is any questions'

as add-on to Dilliganesh:
what viktor show is a built-in function in TIA (not a fb, so it does not need DB)

also output is your scaled value and ret_val is error code. both must be defined, but you can use one temp variable for all ret_val if you need to call this function multiple times.
also don't forget to set Bipolar, it also has to be defined as TRUE or FALSE (but i think it cannot contain constant in ladder)

just FYI, in step7 classic there is SFC104 or SFC105, don't know exatcly but i don't think you use that as you specified s7-1200.

EDIT:
if you write in scl then:

hi victor i know this scale block but ...can u explain how its convert 4-20 mA current signals to 0 to 120 PPM..... i need a explanation about this block

it is pretty well explained in Help section with formula and picture.
Go to Help, search, SCALE (or SCALE_X maybe for s7-1200 cause SCALE is for s7-300/400)

For scaling values If you don't know the basic formulas I really recommend Ron Beaufort artical about it, it's really well explained.

http://www.plctalk.net/qanda/showthread.php?t=15069

I don't know which firmware you have, but with older FW you need 1st to use NORM_X to normalise raw value to 0-1 then use SCALE_X to rescale that to your value cause with older version SCALE_X used only normalised input (i.e. input needed to be between 0-1).
best to check both NORM_X and SCALE_X