Siemens SIMATIC FM 452, Manual

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Encoders
10-6
FM 452 Electronic Cam Controller
C79000-G7076-C452-04
10.3 Absolute Encoders
Single-turn and Multi-turn Encoders
Absolute encoders are grouped as follows:
•
Single-Turn Encoders
Single-turn encoders form the total encoder range on one encoder revolution.
•
Multi-Turn Encoders
Multi-turn encoders form the total encoder range over a number of encoder
revolutions.
Connectable Absolute Encoders
Absolute encoders with a serial interface are supported. Position information is
transferred synchronously using the SSI protocol (synchronous serial interface).
The FM 452 supports only GRAY code. Due to the arrangement of the data bits in
the transferred frames, the data formats ”fir tree”, ”half fir tree” and ”right-justified”
are used.
Encoder Type Frame Length / Type
Single-turn encoder
Single-turn encoders
Single-turn encoders
Multi-turn encoder
Multi-turn encoders
Listen-in
Listen-in
Multi-turn as
Single-turn encoders
Special setting:
13-bit half fir tree
13-bit right-justified
25-bit right-justified
25-bit fir tree
25-bit right-justified
Fir tree
right-justified
25-bit half fir tree
Data transfer
The data rate for data transmission depends on the cable length (see Appendix,
Technical Specifications).
Pulse Evaluation with Absolute Encoders
1 Inkrement (Gebervorgabe) 1 Impuls (FM–Auswertung)