Operating instructions

04/08 Application manual Positioning 105
4.10 Position Comparator
The position comparator compares the current position and the specified positions.
It checks if the actual position is within the specified range (defined by on and off
positions). Via the comparator, logic functions can be controlled or activated, de-
pending on the current position value.
The following signals are set if the current value is in the range between the
On-
Position
1243 and the Off-Position 1244:
− "58 – Position Comparator" and "158 - Inv. Position Comparator" for digital out-
puts
−
"876 – Position Comparator Out" and "877 - Position Comparator Out inverted"
for logic functions
Parameter
Hysteresis 1245 prevents non-defined switching states when the system
has stopped exactly at a switching position. In this case, the output is reset if the
current position is smaller than the “on position minus hysteresis” or greater than
the “off position plus hysteresis”.
Actual position Signal source
58
1)
158
2)
Actual position < On-position - hysteresis 0 1
On-Position
- Hysteresis
< Actual position < On-position last value
On-Position < Actual position < Off-position 1 0
Off-Position < Actual position < Off-position + hysteresis last value
Off-Position
+ Hysteresis
< Actual position 0 1
1)
58 – Position Comparator
2)
158 – Inv. Position Comparator
58 - Position Comparator
0
1
Actual position value
On-Position 1243
Hysteresis 1245 Hysteresis 1245
Off-Position 1244
Parameter Setting
No. Description Min. Max. Fact. sett.
1243 On-Position -2
31
u 2
31
-1 u 0 u
1244 Off-Position -2
31
u 2
31
-1 u 65 536 u
1245 Hysteresis 0 u 2
31
-1 u 182 u
The position comparator is active only if
On-Position 1243 < Off-Position 1244. If
On-Position 1243 ≥ Off-Position 1244, the position comparator will continuously
signal "0".
Application manual Positioning 10504/08