Siemens SIMATIC ET 200M Operating Instructions Manual page 136

Functions
8.2 Time stamping the input signals with IM 153-2
8.2.2.2 Highly precise time stamp with 1 ms precision
Controlling
The following configuration must be authorized for the highly precise time stamping with 1
ms precision:
● Automation system with highly precise time synchronization
● ET 200M with IM 153-2 (as of 6ES7153-2BAx1-0XB0)
● no RS 485 repeater between the DP master and the ET 200M on which input signals are
● Only digital input modules can be used in the ET 200M.
● Only signals from the DI module 6ES7321-7BHxx-0AB0 can be time stamped.
● Input signals that should receive a time stamp must be lined up as seamlessly as
● The start-up time of the ET 200M must be waited for (at least 10 seconds).
● The physics of the encoder must be observed. Different transitions of the input signals
Restrictions
During the following events, the time stamping precision could worsen:
● Processing diagnoses
● Firmware update
● Reading the I&M data
● other acyclic services
Scope
The precision of the time stamping applies throughout the line.
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To do this a clock master, e.g. SICLOCK TM must be available in the automation system.
to be time stamped
– The input delay of all digital inputs for time stamping must be configured identical to
the minimum value (100 μs).
– Process interrupts must be deactivated.
possible as of slot 4, channel 0.
(rise time, spikes, ...) can have different effects on the precision of the time stamping.
Operating Instructions, 12/2008, EWA-4NEB780600602-08
ET 200M