Arithmetic instructions
377
Part III FP Instructions
No. IEC address Set If
R900B %MX0.900.11 for an instant the calculated result is 0.
R9009 %MX0.900.9 for an instant the result exceeds the range of 8-digit
BCD data (overflow).
Error flags
Example
In this example the function has been programmed in ladder diagram (LD) and structured text
(ST).The same POU header is used for all programming languages.
POU header
All input and output variables used for programming this function have been declared in the POU
header.
Body
When the variable start changes from FALSE to TRUE, the function is carried out.
LD
ST
IF DF(start) THEN
F46_DBSUB(subtrahend, output_value);
END_IF;