Siemens SIMATIC ET 200S Operating Instructions Manual page 248

1SSI
4.6 Functions of the 1SSI
Terminating the Latch Function
The latch function must be acknowledged. When the controller program acknowledges the
acceptance of the encoder value, bit 31 is deleted and the encoder value is updated again.
Freezing is then possible again.
Figure 4-3
248
Latch Function
Technological Functions
Operating Instructions, 06/2010, A5E00124867-07