Siemens SIMATIC S5 Manual page 320

STEP 5 Programming
Reading of the input frame (PII) is only outlined. In practice, you would program
the response to specific system states to suit your particular requirements.
One practice-based application has been programmed in the function block.
Using M functions, you can trigger external activities
such as lower drill
raise drill
START
Read input
bytes
Display errors
Read actual values
M 30
yes
output?
no
M 40 yes
output?
no
END
9-32
(M 30 in the example)
(M 40 in the example)
FB 20 - NAME:READ
Reading the mode, M function and status
byte and displaying errors
L
L
L
L
T
Reading the integer and decimal digits
L
L
L
Activate the
L
"Lower drill"
!=F
function
=
L
L
Activate the "Raise
!=F
drill" function
=
BE
IB 64 MODE
IB 65 M FUNCTION
IB 66 STATUS
IB 67 ERRORS
QB 5 DISPLAY
IW 68 INTEGER DIGITS
IW 70 DECIMAL DIGITS
IB 65
KB 30 M30
LOWER DRILL
Q 2.6 ==> LOWER DRILL
IB 65
KB 40 M40
RAISE DRILL
Q 2.7 ==> RAISE DRILL
EWA 4NEB 812 6057-02
IP 266