Siemens IM 153-4 PN, Operating Instructions Manual

Page: 136 / 274

Functions
8.2 Time stamping the input signals with IM 153-2
ET 200M
134
Operating Instructions, 12/2008, EWA-4NEB780600602-08
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
To do this a clock master, e.g. SICLOCK TM must be available in the automation system.
● 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
to be time stamped
● Only digital input modules can be used in the ET 200M.
● Only signals from the DI module 6ES7321-7BHxx-0AB0 can 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.
● Input signals that should receive a time stamp must be lined up as seamlessly as
possible as of slot 4, channel 0.
● 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
(rise time, spikes, ...) can have different effects on the precision of the time stamping.
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.