SCL BYTE arithmetic

Hello.

I try to subtract byte from byte in S7-SCL for classic Step 7 v5.5:

VAR_TEMP

      Temp  :  BYTE;

END_VAR

Temp := BYTE#16#3;
Temp := Temp - BYTE#16#2;

It is not work ! Error during compilation "Invalid types of address" (in line where I try to subtract)

Also, same error when I try to compare two bytes:   Example:  (Temp < BYTE#16#2)

Anybody, please suggest me something !

hdhosseini

Dear user,

If we consider that SCL is ultimately converted to an STL version and STL mostly support INT manipulation , it is wiser to try conversion instruction plus checking byte violation limits.

 note:all variables are bytes

test3:= int_to_byte(BYTE_TO_INT(test2)+ BYTE_TO_INT(test1));

I hope it helps,

hdhosseini

Thanks, but how about subtraction (example:   byte#2 - byte#32) ?  there should be something more simple.

hdhosseini

I am sorry to say there is no simple way, check the attached file from SCL manaul:

test3:=int_to_byte(BYTE_TO_INT(b#16#11) -(BYTE_TO_INT(b#16#2)) );

NOTE:ANY_NUM stands for INT,DINT,REAL

 Yes, thanks, I read it already.

No simple way.

Very sad, because TIA Portal S7-1200 SCL byte arithmetic works fine. But I need it on S7-400 :)

New question published by AutoGen_1800996 is split to a separate thread with the subject Downloaded SCL FB and try to "translate" it - SCL claims that BYTE_TO_INT was missing..

Best regards
Jen_Moderator