IDEC MicroSmart - Manual (Page 338)

20: P ULSE I NSTRUCTIONS
20-10 « FC4A M ICRO S MART U SER ’ S M ANUAL »
Timing Chart for Enable Pulse Counting
This program demonstrates a timing chart of the PWM1 instruction when pulse counting is enabled.
D1
M50
I0
PWM
1 S1
D200
D202 = 1 (enable pulse counting)
• When input I0 is turned on, PWM1 star ts to generate output pulses at the frequency designated by the value
stored in data register D200. The pulse width is determined by the value stored in data register D201. While the
output pulses are sent out from output Q0, internal relay M50 remains on.
• When the quantity of generated output pulses reaches the preset value designated by data registers D203 and
D204, PWM1 stops generating output pulses. Then internal relay M50 turns off, and internal relay M51 turns on.
• If the pulse width ratio value in D201 is changed while generating output pulses, the change takes effect in the
next scan. When changing the pulse width ratio, make sure that the timing of the change is much slower than the
output pulse frequency, so that the pulse width ratio is changed successfully.
• If input I0 is turned off before reaching the preset value, PWM1 stops generating output pulses immediately, then
internal relay M50 turns off and internal relay M51 turns on.
Output Pulse Q0
Pulse Width Ratio D201
PV1
PWR1
Star t Input I0
PWR2 PWR3
Preset Value D203·D204 PV1 PV2 PV3
Pulse Output ON M50
Pulse Output Complete M51
PV2
PWR1 PWR2