An input signal does not turn off No.2
By using two power supplies, a sneak path is configured.
E1 > E2
• Use one power supply.
• To prevent the sneak path, connect a diode as shown below.
A signal incorrectly inputs data
Noise is taken as input data.
• 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.
11.6 Examples of Troubles with the I/O Module