Siemens SIMATIC ET 200S Operating Instructions Manual page 150

1Count5V/500kHz
3.6 Count Modes
When hysteresis becomes active, the 1Count5V/500kHz stores the count direction. If the
hysteresis range is exited in a different direction to the one stored, a pulse is output.
Figure 3-17
Controlling the Outputs Simultaneously with the Comparators
If you have selected a comparison function for the outputs, you can continue to control the
outputs with SET_DO1 or SET_DO2. This allows you to simulate the effect of the
comparison functions on your control program:
• The output is set with the positive edge of SET_DO1 or SET_DO2. However, if the "Pulse
• A negative edge of SET_DO1 or SET_DO2 resets the output.
Note that the comparators are still active and can set or reset the output if the comparison
result changes.
Note
An output set with SET_DO1 or SET_DO2 is not reset at the comparison value (by the
comparator).
150
Example of How Hysteresis Works
on Reaching the Comparison Value" function is selected, only one pulse with the
specified duration is output. When pulse duration = 0, the output can be set with
SET_DO1 or SET_DO2, as long as the count value is located on the comparison value or
hysteresis is active. The SET_DO1 control bit is not permitted with the "Switch at
Comparison Values" output behavior.
Technological Functions
Operating Instructions, 02/2007, A5E00124867-05