74
(e) Case 5
(2) An input signal does not turn on. (AC input module)
(3) A signal incorrectly inputs data.
If excessive noise is periodically generated, setting the response time shorter may be effective.
70ms 20ms
Case
Cause
By using two power supplies, a sneak path has been configured.
Action
• Use one power supply.
• To prevent the sneak path, connect a diode as shown below.
Case
Cause
Stepwise distortions as shown below appear to the zero cross voltage of an input signal (AC).
Action Improve the input signal waveform by using online UPS.
Case
Cause Noise has been taken as input data.
Action
Set the input response time longer. ( Page 68, Section 7.1)
1ms 5ms
If this action is not effective, also take the following two measures.
• To prevent excessive noise, avoid installing power cables together with I/O cables.
• Connect surge absorbers to noise-generating devices such as relays and conductors using the same power supply or take other noise
reduction measures.
E1E2
Input
module
E1>E2
Lamp
Diode
E1
Lamp
E2
DC input
Input
module
Zero cross
voltage
Ex.
Ex.