Statement (I): The term ‘encoder’ is used for a device that provides an analog output as a result of angular or linear displacement. Statement (II): An increment encoder detects changes in angular or linear displacement from some datum position where as an absolute encoder gives the actual angular or linear position.

Statement (I): The term ‘encoder’ is used for a device that provides an analog output as a result of angular or linear displacement. Statement (II): An increment encoder detects changes in angular or linear displacement from some datum position where as an absolute encoder gives the actual angular or linear position. Correct Answer Statement (I) is false but Statement (II) is true

Concept:

• An encoder is a sensing device that provides feedback from the physical world.
• It converts motion to an electrical signal which can be read by some type of control device, such as PLC.
• It has a maximum of 2ⁿ input lines and 'n' output lines, hence it encodes the information from 2ⁿ    inputs into an ‘n’ bit code.
• It generates digital output in response to a linear or angular displacement.

There are two main types of encoders:

1. Linear
2. Rotary

A linear encoder responds to motion along a linear path, whereas a rotary encoder responds to rotational motion.

Linear and rotary encoders are broken down into two main types:

• The incremental encoder
• The absolute encoder  

The incremental encoder

• It generates a pulse for every constant change in input position either linear or angular
• From the plotting of these pulses, we can detect changes in angular or linear displacement from some datum position.

The absolute encoder  

• It generates digital code, corresponding to the input position for both linear/angular position.
• From this digital code, we can find the actual angular or linear position.

Hence from the above explanation, we can say that statement (I) is false but Statement (II) is true.