How to select absolute encoder output signals？！

How to select absolute encoder output signals？

The output signal of the absolute encoder has a parallel multi-core signal output, 4-20mA output, RS485 signal output, SSI synchronous serial signal output, PROFIBUS-DP fieldbus signal output, fieldbus Canopen output.

1. Parallel signal output means how many bits absolute encoder, there are that many root signal output line, high and low output directly represent coding. For absolute multi-turn encoders, the number of bits in the 20 or more, so that the signal cable parallel output may be 20 multi-core, long-distance transmission, the reliability of wiring is reduced, and the encoder 20 outputs a number of centralized power , poor heat dissipation, greatly increases the probability of damage to the encoder.

2.4-20mA analog output, Advantages: simple, all PLC can receive disadvantage: Analog has ripple impact of the single encoder can not see, for a two encoders, the error may be greater than the ripple correction accuracy.

3. RS485 (or Modbus), as is the response type reading mode for two encoders scan cycle, slow response time, reading time may cause poor accuracy error generated.

4. SSI synchronous serial signal transmission cable under the long (50 meters), transmission and data reception clock synchronization has been sacrificed, if the interference signal, anti-interference ability has declined.

5. Fieldbus PROFIBUS-DP, the more mature field bus connection more than 300 Siemens PLC, the signal cable grounding is required, special cable, the total cost (including PLC, cable, encoder, etc.) high.

6. Fieldbus Canopen, specifically for automotive electronics, safety equipment design fieldbus used in lifting equipment, carts ideal for correcting encoder. Disadvantages: relatively new technology, with fewer such an encoder and receiver controller for professional and technical services required, can only be done by a more professional manufacturers. (Such choices, we recommend looking Canopen professional services for manufacturers).

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