Structure And Handling Of The Status Word; Structure Of The Status Word - Siemens SIMATIC S5 Manual

IP 265
4.3.2

Structure and Handling of the Status Word

The operating state and possible error states of the IP 265 can be recognized via the status word.
You can evaluate the following in the status word of the IP 265
• The status of IP 265,
• Possible hardware errors of the IP 265,
• Loading errors of the IP 265 and
• Illegal instructions in the control word.
General structure of the status word:
Byte 0
Byte 1
7 6
Status bits
Bits that may contain additional information
Bits for COM 265-internal use
Note
The information in the status word is always a response to the control data of the
preceding data cycle. However, they are not an "echo" of the instruction in the control
word. Bits 0 and 1 in byte 0 of the status word always display the current operating state
of the IP 265.
EWA 4NEB 812 6130-02a
5 4 3 2 1
Figure 4-7. Structure of the Status Word
Control bit:
1: IP 265 monitored by COM 265
or "loading from memory submodule"
0: IP 265 not monitored by COM 265 and not
"loading from memory submodule":
IP 265 and CPU user program may
exchange input and output data.
Operating status
display:
0
General Operation
Bit 1 Bit 0 IP 265
0 1
STOP
1 0
RUN
4-9