Sensors
If one were to compare a machine to the human body, a sensor would be something akin to nerves. A sensor is a device that takes in some type of input from the outside world and converts it to an electrical signal that a PLC module can read and transmit to the CPU module.
Generally, sensors will produce an analog value or an on/off value. An analog sensor is a device that will produce an electrical signal in proportion to its reading. For example, a light sensor, such as a photoresistor, will produce an electrical signal that is proportional to the amount of light that is picked up. In a more lay sense, an analog device is one in which the output signal will vary. Common analog sensors are as follows:
- Light sensors
- Strain gauges
- Sound gauge
- Pressure sensors
- Position sensor
- Temperature sensors
On the other end of the spectrum are sensors that produce an on/off value. These types of sensors are like switches. An example of a digital signal...
