Difference between revisions of "Using BiSS encoder"

Revision as of 17:52, 9 February 2018

BiSS Interface is an open standard used by many encoder feedback device manufacturers. IONI Pro servo drive supports BiSS encoders starting from firmware version 1.6.0.

BiSS support details

As BiSS is quite wide standard supporting large number of different setups and device types, it is important to acknowledge the properties BiSS interface in GD drives. In current firmware, following properties apply:

• Support BiSS B and BiSS C devices
• Read of multi-turn (MT) and single-turn (SD) data from encoder
• Resolution
  • Single-turn resolution from 6 to 30 bits (however, higher than 30 bit resolution is still compatible, lowest bits are just ignored)
  • Multi-turn resolution from 0 to 16 bits
  • The sum of ST+MT bits must be between 6 and 32 bits
• Error detection by the means of
  • No response from encoder. Drive sets timeout or loss of connection error if encoder does not respond with a "start bit" in 20 µs.
  • Bit transfer error occurred causing large position jump to trigger tracking error
• Clock rate 5.1 MHz
• Support utilizing absolute position information from the encoder
  • To skip axis homing procedure
  • To initialize rotary motor immediately (no Phasing needed)

Current firmware version limitations:

• No data CRC verification. Suggested workaround is to apply sensible tracking error limits.
• No daisy chaining encoders is supported. Only one encoder may be connected to a drive.
• No cable delay compensation implemented. Less than 5 meter cable is recommended, however up to 10 meters have been tested with success.

List of tested BiSS encoders:

If you have tested another kind of encoder, please help us to inform the community by letting us know your encoder model and result by dropping a message into Granite Devices support.

SimuCUBE supports BiSS encoder resolutions up to 21 bits (2M counts/rev).

Wiring BiSS encoder

BiSS encoder typically has 6 mandatory wires consisting:

• Power supply lines (2 wires)
• Clock input (2 wires)
• Data output (2 wires)

Connection to IONI Pro drive by following table:

Refer to IONI & IONICUBE user guide for more info on wiring encoders.

Cable termination resistors may be necessary for reliable operation, for more details, see Terminating differential encoder lines.

Configuration

BiSS parameters in Granity. Example settings for Hengstler AD36 (AD36/1219AF.0XBI0:5653).

To configure BiSS, use Granity version 1.11.0 or later. Configuration steps:

1. Find out encoder MT and ST resolutions from encoder manufacturer's data sheet
2. Select Serial data encoder from Feedback deviceFBD
3. Select corresponding protocol (BiSS B, BiSS C) from Serial encoder typeFBS
4. Set number of MT and ST bits into parameters Single-turn bitsFBST and Multi-turn bitsFBMT