Comparator (Only In Standard Mode) - Siemens SIMATIC ET 200S Operating Instructions Manual

4.6.6

Comparator (Only in Standard Mode)

Description
The encoder position that is detected can be compared with up to two loadable values
(without hysteresis). Both comparison results are stored in the feedback interface. The
appropriate comparator becomes active only after the comparison value is loaded.
You set the two comparators in the Comparator 1 and Comparator 2 parameters:
Setting
Not active
In the up direction
In the down direction
In both directions
As soon as you load a comparison value, the comparison result is deleted and is then
entered in accordance with the directional setting.
Note
Only one control bit can be set at a particular time:
CMP_VAL1 or CMP_VAL2.
Otherwise, the ERR_LOAD error is reported until both control bits are deleted.
Technological Functions
Operating Instructions, 02/2007, A5E00124867-05
Effect on the Result of Comparison (CMPx)
The encoder value is not compared.
The feedback bit CMPx = 0.
The encoder value is compared in the up direction (UP).
If the encoder value ≥ the comparison value, the feedback bit CMPx = 1.
•
If the encoder value < the comparison value, the feedback bit CMPx = 0.
•
If the direction is down, the feedback bit CMPx remains unchanged.
•
If no change is detected in the encoder value, the feedback bit CMPx remains
•
unchanged.
The encoder value is compared in the down direction (DN).
If the encoder value ≤ the comparison value, the feedback bit CMPx = 1.
•
If the encoder value > the comparison value, the feedback bit CMPx = 0.
•
If the direction is up, the feedback bit CMPx remains unchanged.
•
If no change is detected in the encoder value, the feedback bit CMPx remains
•
unchanged.
The encoder value is compared in both directions.
If the direction is up, the following conditions apply:
If the encoder value ≥ the comparison value, the feedback bit CMPx = 1.
•
If the encoder value < the comparison value, the feedback bit CMPx = 0.
•
If the direction is down, the following conditions apply:
If the encoder value ≤ the comparison value, the feedback bit CMPx = 1.
•
If the encoder value > the comparison value, the feedback bit CMPx = 0.
•
If no change is detected in the encoder value, the feedback bit CMPx remains
•
unchanged.
1SSI
4.6 Functions of the 1SSI
235