Omron SYSMAC C Series User Manual page 9

1 Console screws
These stud screws are removed with a flat-bladed screwdriver to open
the cover for initial setting and maintenance purposes.
2 Input terminals
These terminals are used to connect the wiring carrying input signals
from the devices of the controlled system.
3 Input/output indicators
These LEDs show the state of the signals (by turning red when ON and
dark when OFF) for each of the input and output terminals.
4 LED indicators (POWER, RUN, ERROR/ALARM)
These LEDs light up to show the state of the main power supply
(ON/OFF), when the C20 is in the RUN mode, and if any error has
occurred.
5 Power terminals
These terminals connect the AC or DC power source and are grounded at
a resistance of less than 100Q.
6 Output terminals
These terminals are used to connect the wiring carrying output signals
from the CPU to the output devices.
7 Connector for expansion 1/0 units
This is available only on the expandable type CPU and is used to connect
to expansion I/O units to increase the number of I/O points.
8 Connector for peripheral devices
This connects the programming console or another peripheral device.
PC