Dear Aret/Pandiani

I have an issue totally related to your discussion about SER using IM153-2 High Feature:

I have a CPU414 (not redundant) and I want to use it separately for SER. my desired resolution for SER is 1ms. That means  recording the signal  changes below 1 ms is not important. Assuming cycle time of CPU set to 20 ms, (regarding 15 buffers inside IM each one containing 20 messages) the possibility of loosing messages seems to be nearly zero.  Is it true? How could it happens to lose a message in this condition?

sincerely

Mazdak

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Split from Help needed for 1msec Sequence of Events Recording.

Hi, 

See this for example:

Buffering of Process Messages including Time Stamps with ALARM_7B

Also background info about the case in general (maybe pay extra attention to chapter "4.3 Special features of the interface module/Message loss" ):

SIMATIC Process Control System PCS 7 High-precision time stamping (V8.1)

I hope I could help!