Significance Of Special Messages - Siemens SIMATIC ET 200M Operating Instructions Manual

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
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.
• During start up / restart / cold start the IM 153-2 again outputs process interrupts for 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
– Current signal status for all input signals that are to be stamped ("INCOMING" or
– Special message "Start-up data END"
With redundant mode
In redundant mode it also applies that:
• during a changeover between active and passive IM 153-2 the time stamping is
interrupted. With the special message "Changeover with redundant BEGIN / END" the
period of interruption is displayed.
• If the communication between the two IM 153-2 is interrupted in redundant mode, the
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.
ET 200M
Operating Instructions, 04/2022, EWA-4NEB7806006-09
"OUTGOING" in accordance with the configured edge)
"OUTGOING" in accordance with the configured edge)
8.2 Time stamping the input signals with IM 153-2
Functions
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