Chapter 5 CPU Module
5-
ేె
3) Up-down counter
The current value is increased with the rising edge of up-count input signal, and decreased with the rising edge of down-
count input signal. The counter output relay is turned on when the current value is equal or greater than the preset value.
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.
REMARK
1. Maximum counting speed
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))(CspeedcountingMaximum max (
1
100
st
n
×=
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,
)
T2T1
T1
n (%100×
+
=
If T1 > T2,
)
T2T1
T2
n (%100×
+
=
U CTD Cxxx
D
R <S> xxxx
U CTR Cxxx
R <S> xxxx
Down Input condition
Reset condition
Up Input condition
Input condition
Reset condition
T1 T2
OFF
ON