Basics of Signal in Automation

Fan stateHuman’s replySignal state24v sensor reply
OFFON0 0V
ONYes124V

Note:

A real time electrical switch is an example of digital provider.

Some more example:

Floater, limit switch, electrical switch, toggle switch etc.

Analog signal

The signal which is in the form of word or additional parameter with ON or OFF.

In other word the signal which deals with low, medium high.

Analog sensor.

The device which sense any parameter and gives out-put in the form of

0 to 1 (0, 0.5, and 1).

Example

Real time example:

If we ask any one. In what speed fan is running.

He/ She may reply with slow or medium or high speed.

Same question ask with a digital sensor deal with 24vdc.

it replies with”24V” for “high speed” state, “0V” for “OFF” state,

“8V” for “slow speed” state, “16V” for “medium” state

Comparison of each response.

http://www.geekfellows.com/

Fan stateHuman’s replySignal state24v sensor reply
OFFNo0 0V
Slow speedSlow0.3 8V
Medium speedMedium0.6 16V
High speedHigh1 24V

Note:

A real time electrical fan regulator is an example of analog signal provider.

Some more example:

Level transmit or, flow sensor, current sensor etc.