Siemens CPU 412-1 Instruction Manual page 16

Status Word (16 Bits)
The status word bits are evaluated or set by the instructions.
The status word is 16 bits long.
Bit Assignment
0
1
2
3
4
5
6
7
8
9 to 15 Unassigned
S7-400 Instruction List
A5E00267845-01
FC First check bit
RLO Result of logic operation
STA Status
OR Or (AND before OR)
OS Stored overflow
OV Overflow
CC 0 Condition code 0
CC 1 Condition code 1
BR Binary result
–
Description
Registers
14