Position reconstruction on switch-on only works with absolute encoder - Definition of absolute encoder
Question:
With which encoder types is the position reconstruction function useful?
Answer:
The position reconstruction is used to restore the actual position with reference to the reference position when the machine is switched on. The reference status is therefore retained (reference known) and the machine can be operated without re-referencing.
The position reconstruction only works as expected with encoder types that can provide absolute position information.
Due to the principle of purely incremental encoder types (SinCos encoder, TTL encoder) position changes cannot be recorded when switched off. Each time the encoder is switched on, position information is therefore lost and an offset to the reference position occurs. The offset can gradually increase from time to time
The donor-type must be suitable, the absolute Position at least within a whole rotation .
Suitable absolute encoders:for position reconstructionspan aria-hidden="true">
Absolute value encoder - Hiperface-SinCos (Singleturn, Multiturn)
Resolver types with pole pair number = 1 (i.e. two-pole resolvers)
Special SinCos encoder with stroke count/period count = 1 (the SinCos evaluation enables the representation of the absolute position over one revolution)
Not suitable for position reconstruction encoder types:
Higher-pole resolvers with pole pair number >=2 (i.e. >= 4-pole resolver)
Incremental encoders (SinCos, TTL) with a line count >= 2
