BLOCK
CountType
INPUT
RESET
ERROR
OVERFLOW
LIMIT1 … 4
CounterLimit1...4
MaxValue
OnMaxValue
InitialValue
VALUE
Operation
Counter
Overflow
Detection
Limit
Check
Error
Detection
IEC12000625_1_en.vsd
IEC12000625 V1 EN
Figure 210: Logic diagram
The counter can be initialized to count from a settable non-zero value after reset of the
function. The function has also a maximum counted value check. The three possibilities
after reaching the maximum counted value are:
• Stops counting and activates a steady overflow indication for the next count
• Rolls over to zero and activates a steady overflow indication for the next count
• Rolls over to zero and activates a pulsed overflow indication for the next count
The pulsed overflow output lasts up to the first count after rolling over to zero, as
illustrated in figure
211.
IEC12000626_1_en.vsd
Max value +3
1 2
...
...
...
...
Overflow indication
Actual value
Counted value
IEC12000626 V1 EN
Figure 211: Overflow indication when OnMaxValue is set to rollover pulsed
Section 12 1MRK 511 287-UUS A
Monitoring
454
Technical manual