Delta C2000 Series User Manual page 514

Example 7: Oscillating circuit
Oscillating circuit with a period of T+ T
The figure below shows a very simple ladder diagram. When starting to scan the Y1 NC
contact, because the Y1 coil has lost power, the Y1 NC contact will be closed. When the Y1
coil is then scanned, it will be electrified, and the output will be 1. When the Y1 NC contact is
scanned in the scanning cycle, because Y1 coil is electrified, the Y1 NC contact will be open,
the Y1 coil will then lose power, and the output will be 0. Following repeated scanning, the
output of Y1 coil will have an oscillating waveform with a period of T(On)+ T(Off).
Y1
Oscillating circuit with a period of nT+ T
The program of the ladder diagram shown below uses timer T0 to control coil Y1's electrified
time. After Y1 is electrified, it causes timer T0 to close during the next scanning cycle, which
will cause the output from Y1 to have the oscillating waveform shown in the figure below.
Here n is the timer's decimal setting value, and T is the clock cycle of the timer.
X0
T0
Example 8: Flashing circuit
The following figure shows an oscillating circuit of a type commonly used to cause an
indicator light to flash or a buzzers to buzz. It uses two timers to control the On and Off time
of Y1 coil. Here n1, n2 are the timing set values of T1 and T2, and T is the clock cycle of the
timer.
X0
T1
X0
Example 9: Triggering circuit
In the figure below, a command consisting of the differential of the rising edge of X0 causes
coil M0 to generate a single pulse for
electrified during this scanning cycle. Coil M0 loses power during the next scanning cycle,
and NC contact M0 and NC contact Y1 are both closed. This causes coil Y1 to stay in an
electrified state until there is another rising edge in input X0, which again causes the
electrification of coil M0 and the start of another scanning cycle, while also causing coil Y1 to
Y1
Y1
TMR T0 Kn
Y1
T2
T1
TMR
T2
TMR
T1
Y1
16-23
Chapter 16 PLC Function Applications
Y1
T T
X0
Y1
nT
Kn1 X0
Kn2
Y1
n1*T
T (length of one scanning cycle), and coil Y1 is
C2000 Series
T
n2*T