Chapter 5 Power Supply / CPU
5-13
4) Ring
counter
-. The current value is increased with the rising edge of the counter input signal, and the counter output relay is turned on
when the current value reaches the preset value. Then the current value and counter output relay is cleared as 0 when
the next counter input signal is applied.
5) Maximum counting speed
(1) The maximum counting speed of counter is determined by the length of scan time. Counting is possible only when the
on/off switching time of the counter input signal is longer than scan time.
times/sec)
(
1
100
)
(C
speed
counting
Maximum
max
s
t
n
×
=
where, n : duty (%), t
s
: scan time
(2) Duty
Duty is the ratio of the input signal’s on time to off time as a percentage.
If T1
≤
T2,
)
T2
T1
T1
n
(%
100
×
+
=
If T1 > T2,
)
T2
T1
T2
n
(%
100
×
+
=
T1 T2
OFF ON
OFF