Siemens SIMATIC ET 200M Operating Instructions Manual page 160

Functions
8.2 Time stamping the input signals with IM 153-2
8.2.4.8 Significance of special messages
With an activated time stamping, the IM 153-2 can supply the following special messages:
● If all 15 data records of the IM 153-2 are full, then the IM 153-2 cannot save any further
● During start up / restart / cold start the IM 153-2 again outputs process interrupts for
With redundant mode
In redundant mode it also applies that:
● during a changeover between active and passive IM 153-2 the time stamping is
● If the communication between the two IM 153-2 is interrupted in redundant mode, the
8.2.4.9 Diagnosis for time stamping
You can obtain information on the status of the time stamping by reading the data record 240
from the IM 153-2 interface module. You read via DS_READ-240.
158
messages. The messages are lost.
The IM 153-2 enters the last message, the special message "Buffer overflow
INCOMING". When a data record is clear, the IM 153-2 enters the first message in the
data record - the special message "Buffer overflow OUTGOING". Messages that occur
between the buffer overflow and the clearance of a data record are lost.
those data records that were occupied before the start up, but have not yet been
collected.
In the first free data record the IM 153-2 enters the following messages:
– Special message "Start-up data BEGIN"
– Signal changes that occur immediately before a master STOP ("INCOMING" or
"OUTGOING" in accordance with the configured edge)
– Current signal status for all input signals that are to be stamped ("INCOMING" or
"OUTGOING" in accordance with the configured edge)
– Special message "Start-up data END"
interrupted. With the special message "Changeover with redundant BEGIN / END" the
period of interruption is displayed.
special message "Loss of information in the case of redundancy INCOMIING" is output.
As soon as the communication between the active and passive IM 153-2s is possible
again, the special message "Loss of information in the case of redundancy OUTGOING"
is output. It is not possible to adjust this afterwards, as changing over to the error state of
the interface module IM 153-2 could lead to message loss.
Operating Instructions, 12/2008, EWA-4NEB780600602-08
ET 200M