High-Speed Counters - ABB CL Series Applications Manual

1SVC 440 795 M0100

High-speed counters

You can use the high-speed counters to count high
frequency signals reliably.
The logic relay provides two high-speed up/down counters
C13 and C14 for use as required. The high-speed counter
inputs are permanently connected to the digital inputs I1 and
I2. This counter relay allows you to count events
independently of the cycle time.
The high-speed counters allow you to enter an upper
threshold value as a comparison value. The C13 and C14
high-speed counters are not dependent on the cycle time.
Counter frequency and pulse shape
The maximum counter frequency is 1 kHz.
The signals must be square waves. We recommend a mark-
to-space ratio of 1:1.
If this is not the case:
The minimum mark-to-space ratio is 0.5 ms.
t = 0.5 x
min
t = minimum time of the pulse or pause duration
min
f = maximum count frequency (1 kHz)
max
h High-speed counters operate independently of the
program cycle time. The result of the actual value setpoint
comparison is only transferred once every program cycle
for processing in the circuit diagram.
The reaction time in relation to the setpoint/actual value
comparison can therefore be up to one cycle in length.
Wiring of a high-speed counter
The digital inputs have the following assignment:
• I1: high-speed counter input for counter C13.
• I2: high-speed counter input for counter C14.
High-speed counters,
CL-DC1, CL-DC2
1
f
max
125