ENCODERS
1.Intro
Encoders can be either absolute or incremental,
1.1 Absolute encoder
Absolute encoders have a unique code for each shaft position. The absolute encoder interprets a system of coded tracks to create position information where no two positions are identical. Another feature is that absolute encoders do not lose position whenever power is switched off. Single-turn encoders are used for position verification with a single revolution of the encoder axis
Absolute encoders have a number of advantages. First is the non-volatility of memory. An absolute encoder works as a non-volatile position verification device. True position is not lost if power is lost or the system moves while power is switched off. A continuous reading of position is not needed. This is specifically useful in those applications, such as satellite-tracking antennas, where position verification is key.
1.2 Incremental encoders
An incremental encoder provides a specified amount of pulses in one rotation of the encoder. The output can be two lines of pulses (an “A” and “B” channel) that are offset in order to determine rotation direction. This phasing between the two signals is called quadrature. An disadvantage is that incremental encoders lose position whenever power is switched off.
2. Principle
2.1 The principle of an incremental encoder
An incremental encoder generates a pulse for each incremental step in it's rotation.
2.2 The principle of an absolute encoder
An absolute encoder generates a code for each step in it's rotation, it has a disk with a gray code, that means with every code change only one codetrack change.
3 How are both encoders used by FreeGo2