Before turning on or off the external power supply, check that the rise time of the external power supply is 10ms or more.
Then, install a switch (SW1) to the primary side of the external power supply.
When installing the switch to the secondary side, connect a capacitor and resistor, and increase the rise time (10ms or more).
• Sink output
• Source output
R1:Several tens of ohms
Power capacity ≥ (External power supply current
C1:Several hundreds of microfarads 50V
R1 = 40Ω, C1 = 300μF
Time constant is calculated as shown below.
C1 × R1 = 300 × 10
= 12 × 10
*1 For details on the current consumption of the external power supply for output part to be used, refer to the performance specifications.
*2 Select the power capacity of resistor to be 3 to 5 times as large as the actual power consumption.
11.5 Examples of Troubles with the I/O Module
× Resistance value × (3 to 5)