6
INSTALLATION AND WIRING
This chapter describes the installation and wiring of the I/O module.
6.1
Before Using the I/O Modules
Input modules
Precautions common to all input modules
■Number of simultaneous ON points
The number of input points that can be turned on at the same time varies depending on the input voltage and ambient
temperature. Refer to the maximum number of simultaneous input points of the specifications of each input module. (
Page 16 Performance Specifications)
Precautions when using the DC input module
■Measures against back EMF
When connecting an inductive load, connect a diode in parallel with the load. Use the diode that satisfies the following
conditions:
• A reverse breakdown voltage is ten or more times as high as the circuit voltage.
• A forward current is two or more times as high as the load current.
Positive common
IN
Inductive
load
COM
6 INSTALLATION AND WIRING
44
6.1 Before Using the I/O Modules
Negative common
IN
Inductive
load
COM