Siemens SIMATIC S5 Manual page 317

IP 266
FB 23 - FORWARD/REVERSE
Two inputs are scanned in this FB to gather the information required to program
the auxiliary and edge flags. The inputs for FORWARD and REVERSE are ORed.
START
Process auxiliary and
edge flags as
function of the
FORWARD or
REVERSE input
yes
Edge flag = 0?
no
yes
Forward?
no
yes
Reverse?
no
END
EWA 4NEB 812 6057-02
FB 23 - NAME:FWDREV
Programming the auxiliary and edge flags
for the FWD/REV functions
Programming the edge and auxiliary flags
Edge flag not yet set abort
Load bit 2 = 1
(QB 65) into FY 6
Jump in dependence on the keys for FWD
and REV
Load bit 3 = 1
(QB 65) into FY 6
Load start command
M001
M002
STEP 5 Programming
O I 3.3 FORWARD
O I 3.4 REVERSE
AN F 4.4
= F 4.5
O I 3.3 FORWARD
O I 3.4 REVERSE
= F 4.4
AN F 4.5
BEC
A I 3.3
JC =M001
A I 3.4
JC =M002
BEU
L KB 4 FWD command
T FY 6
BEU
L KB 8 REV command
T FY 6
BE
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