Siemens SIMATIC ET 200S Operating Instructions Manual page 35

The latch value is always the exact count at the time of the positive edge on the digital input
DI.
The stored count rather than the current count is indicated in the feedback interface. The
STS_DI bit indicates the level of the latch signal.
Direct loading of the counter does not cause the indicated stored count to be changed.
In isochrone mode, the count that was latched at the time of the last positive edge before T
is displayed in the feedback interface.
When you close the SW gate, the effect is either canceling or interrupting, depending on the
parameter assignment. The digital input DI remains active even when the SW gate is closed.
Further possible causes of parameter assignment errors with the latch function:
• Incorrect parameter assignment of the digital output function (Function DI)
Modified User Data Interface
If the 1Count24V/100kHz is inserted behind an IM 151 that supports the reading and writing
of wider user data interfaces, the current count value can be read from bytes 8-11 of the
feedback interface.
See also
Overview (Page 21)
Technological Functions
Operating Instructions, 02/2007, A5E00124867-05
1Count24V/100kHz
2.6 Count Modes
i
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