Encoders

For the encoders, 3 different ways for determining the position are available.

1. Absolute position without overflow counter
2. Single-turn absolute position
3. Incremental evaluation

Absolute position without overflow counter

• Operating principle:
• The scaling (configuration) and the offset determined during referencing are used for conversion into user units between the encoder and absolute position reference systems.
• Use:
• All rotary or linear absolute encoders, no incremental encoders.
• Limitation:
• The measuring range of the encoder must clearly cover the travel path. A plausibility check is performed automatically during startup. When using motor encoders, the gear ratio to the track must be taken into account.
• Behavior when switching on:
• If referencing was performed before switch-off, the encoder is immediately referenced when switched on.
• Replacement of the CSA31A safety option:
• Referencing is retained.
• Replacement of the encoder:
• With linear encoder:
• Referencing is retained
• With rotary encoder:
• New referencing is required

Single-turn absolute position

• Operating principle:
• The unique position value over one revolution (single turn) is mapped to a modulo range (scaling determined by configuration) and to an offset determined by referencing.
• Use:
• All rotary absolute encoders (single-turn absolute).
• Limitation:
• The encoder must be installed in the application in such a way that its single-turn range maps a logical revolution (e.g. of a rotary table). The single-turn measuring range of the encoder must correspond exactly to the modulo range in user units after rescaling to user units. There must not be a division remainder during the conversion. Under this condition, each single-turn raw position value is uniquely mapped to an absolute position in user units within the configured modulo range.
• Behavior when switching on:
• If referencing was performed before switch-off, the encoder is immediately referenced when switched on.
• Replacement of the CSA31A safety option:
• If referencing was performed before switch-off, the encoder is immediately referenced when switched on.
• Replacement of the encoder:
• New referencing is required.

Incremental evaluation

• Operating principle:
• The position value is continuously updated in increments. This also applies to HIPERFACE^® encoders and SSI absolute encoders. A HIPERFACE^® encoder connected as encoder 2 must be evaluated in increments.
• Use:
• All encoders.
• Limitation:
• Referencing is required after each activation.
• Behavior when switching on:
• The encoder must be referenced. No safety sub-function based on an absolute position can be used during this time.
• Replacement of the CSA31A safety option:
• New referencing is required.
• Replacement of the encoder:
• New referencing is required.