Siemens SIMATIC ET 200SP Manual page 13

Capture
You can configure an external reference signal edge that triggers the saving of the current
counter value as Capture value. The following external signals can trigger the Capture
function:
● Rising or falling edge of a digital input
● Both edges of a digital input
● Rising edge of the N signal at the encoder input
You can configure whether counting continues from the current counter value or from the
start value after the Capture function.
Synchronization
You can configure the edge of an external reference signal to load the counter with the
specified start value. The following external signals can trigger a synchronization:
● Rising or falling edge of a digital input
● Rising edge of the N signal at the encoder input
● Rising edge of the N signal at the encoder input depending on the level of the assigned
Hysteresis
You can specify hysteresis for the comparison values, within which a digital output will be
prevented from switching again. An encoder can come to a standstill at a specific position,
and slight movements may make the counter value fluctuate around this position. If a
comparison value or a counting limit lies within this fluctuation range, the corresponding
digital output will be switched on and off with corresponding frequency if hysteresis is not
used. The hysteresis prevents these unwanted switching operations.
Technology Module TM Count 1x24V (6ES7138‑6AA00‑0BA0)
Manual, 10/2013, A5E33002339-AA
digital input
Product overview
2.2 Functions
13