ABB ACSM1 Series, Firmware Manual

Page: 250 / 334

Standard function blocks
250
Counters
CTD
(10047)
Illustration
Execution time 0.92 µs
Operation The counter output (CV) value is decreased by 1 if the counter input (CD) value
changes from 0 -> 1 and the load input (LD) value is 0. If the load input value is 1, the
preset input (PV) value is stored as the counter output (CV) value. If the counter output
has reached its minimum value -32768, the counter output remains unchanged.
The status output (Q) is 1 if the counter output (CV) value < 0.
Example:
Inputs Counter input (CD): Boolean
Load input (LD): Boolean
Preset input (PV): INT
Outputs Status output (Q): Boolean
Counter output (CV): INT
CTD_DINT
(10046)
Illustration
Execution time 0.92 µs
CTD
93
TLA1 1 msec (1)
LD
>CD
PV
CV
CV(93)
Q
Q(93)
LD CD PV Q CV
prev
CV
0 1 -> 0 10 0 5 5
0 0 -> 1 10 0 5 5 - 1 = 4
1 1 -> 0 -2 1 4 -2
1 0 -> 1 1 0 -2 1
0 0 -> 1 5 1 1 1 -1 = 0
1 1 -> 0 -32768 1 0 -32768
0 0 -> 1 10 1 -32768 -32768
CV
prev
is the previous cycle counter output value.
CTD_DINT
94
TLA1 1 msec (1)
LD
>CD
PV
CV
CV(94)
Q
Q(94)