Siemens SIMATIC ET 200S Operating Instructions Manual page 141

If you have assigned synchronization, the positive edge of a reference signal on the input
sets the 1Count5V/500kHz to the load value.
You can select between once-only and periodic synchronization ("Synchronization"
parameter).
The following conditions apply:
• The counting mode must have been started with the SW gate.
• The "Enable synchronization CTRL_SYN" control bit must be set.
• In once-only synchronization, the first edge loads the1Count5V/500kHz with the load
• In periodic synchronization, the first edge and each subsequent edge load the
• After successful synchronization, the STS_SYN feedback bit is set and the SYN LED
• The signal of a bounce-free switch can serve as the reference signal.
• The STS_DI feedback bit indicates the level of the reference signal.
In isochrone mode, the set feedback bit STS_SYN indicates that the positive edge on the
digital input was between time T
Technological Functions
Operating Instructions, 02/2007, A5E00124867-05
value after the enable bit is set.
1Count5V/500kHz with the load value after the enable bit is set.
comes on. The RES_STS control bit resets the feedback bit and switches the LED off.
in the current cycle and T
i
1Count5V/500kHz
3.6 Count Modes
in the previous cycle.
i
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