The Role of the PC
Section 1-2
1-2-1 Input Devices
PCs can receive inputs from either automated or manual devices. The PC could
receive data from the user via a pushbutton switch, keyboard, or similar device.
Automated inputs could come from a variety of devices: micro-switches, timers,
encoders, photoelectric sensors, and so on. Some devices, like the limit switch
shown below, turn ON or OFF when the equipment actually makes contact with
them. Other devices, like the photoelectric sensor and proximity sensor shown
below, use other means, such as light or inductance, in order to get information
about the equipment being monitored.
Photoelectric Sensor
Proximity Sensor
Limit Switch
1-2-2 Output Devices
A
PC can output to a myriad of devices for use in automated control. Almost any
-
-
thing that you can think of could be controlled by a PC. Some of the most com
mon devices are motors, solenoids, servomotors, stepping motors, valves,
switches, indicator lights, buzzers, and alarms. Some of these output devices,
such as the motors, solenoids, servomotors, stepping motors, and valves, affect
the controlled system directly. Others, such as the indicator lights, buzzers, and
alarms, provide outputs to notify personnel operating or monitoring the system.
Solenoid
Servomotor
Stepping Motor
3
OMRON [ OMRON ELECTRONICS LLC ]
