Condition Code Generation - Siemens SIMATIC S5-115U User Manual

Simatic s5 series cpu 941-7ub11 cpu 942-7ub11 cpu 943-7ub11 and cpu 943-7ub21 cpu 944-7ub11 and cpu 944-7ub21
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S5-115U Manual
8.4

Condition Code Generation

The processor of the S5-115U programmable controller has the following three condition codes:
CC 0
CC 1
OV
(overflow)
The following operations affect the condition codes:
comparison operations
arithmetic operations
shift operations
some conversion operations
The state of the condition codes represents a condition for the various jump operations.
Condition Code Generation for Comparison Operations
Execution of comparison operations sets condition codes CC 0 and CC 1 (see Table 8-32). The
overflow condition code is not affected. However, comparison operations affect the RLO. When a
comparison is satisfied, the RLO is 1. Consequently, the conditional jump operation "JC" can also
be used after a comparison operation.
Table 8-32. Condition Code Settings for Comparison Operations
Contents of ACCUM 2 as
Compared to Contents
of ACCUM 1
Equal to
Less than
Greater than
EWA 4NEB 811 6130-02b
Condition Codes
CC 1
CC 0
0
0
0
1
1
0
STEP 5 Operations
Possible
Jump Operations
OV
JZ
JN, JM
JN, JP
8-73

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