Evaluating Conditions Using AND, OR and EXCLUSIVE OR
35
S7-400 Instruction List
A5E00267845-01
Evaluating Conditions Using AND, OR and EXCLUSIVE OR
All logic instructions generate a result (new RLO). The first instruction in a logic string generates the new RLO from the signal state
scanned. The subsequent logic instructions generate the new RL from the signal state scanned and the old RLO. The logic string ends with
an instruction which limits the RLO (e.g. a memory instruction); that is, the FC bit is set to zero.
Length
Execution Time in s
tion
ID
CPU 412 CPU 414 CPU 416 CPU 417
A/AN
O/ON
X/XN
==0
AND/AND NOT
OR/OR-NOT
EXCLUSIVE OR/ EXCLUSIVE-OR-NOT
Result=0
(A1=0 and A0=0) 1 0.1 0.06 0.04 0.03
>0 Result>0
(CC1=1 and CC0=0)
1 0.1 0.06 0.04 0.03
<0 Result<0
(CC1=0 and CC0=1)
1 0.1 0.06 0.04 0.03
<>0
Result00
((CC1=0 and CC0=1) or (CC1=1 and
CC0=0))
1 0.1 0.06 0.04 0.03
Status word for: A/AN/O/ON/X/XN BR CC1 CC0 OV OS OR STA RLO /FC
Instruction evaluates: – Yes Yes – – Yes – Yes Yes
Instruction affects: – – – – – Yes Yes Yes 1