BiSS interface



The open source BiSS interface (bidirectional/serial/synchronous) is based on a protocol which implements a real time interface. It enables a secure serial digital communication between controller, sensor and actuator. The BiSS protocol is designed in B mode and C mode (continuously bidirectional mode). It is used in industrial applications which require transfer rates, safety, flexibility and a minimized implementation effort. The BiSS interface has roots in SSI and a simplified INTERBUS. The proprietary standards, Hiperface and EnDat are competing solutions.

Application

 * Position sensor system
 * Rotary encoder (absolute encoder)
 * Linear position sensors (absolute encoder)
 * Drive control (motor feedback)
 * Intelligent sensor system (smart sensors)
 * Robotics

BiSS features

 * Open source
 * Hardware compatible for SSI standard (synchronous serial interface)
 * Cyclic reading of sensor data up to 64 bit per slave
 * Transmission of status data, parameter, measured temperature value, configuration description, etc.
 * Isochronal, real time capable data transmission
 * bidirectional communication with two unidirectional lines
 * Point-to-point or multi-slave networks
 * Maximum user data rate, transmission data depending on driver and line of e.g. RS-422: 10 MHz, 1 km; LVDS: 100 Mbit/s
 * Independent of the applied physical layer
 * CRC secured communication (sensor data and control data secured separately)

Characteristics of BiSS C

 * Continuous sensor data transmission without interruption while using control data
 * Activation of actuators in bus during sensor data transmission
 * Broader standardization through BiSS profiles, BiSS EDS (electronic data sheet), BiSS USER DATA, etc.
 * Full compatibility of BiSS identifier (already defined in BiSS B)

History of BiSS in position sensor system

 * BiSS was showcased in 2002 by its founders iC-Haus GmbH
 * Since BiSS B is not motor feedback compatible, BiSS C has been preferred in the market
 * All patent cases against BiSS B were dropped in 2012:
 * EP 0790489B1: "Mode switching by frequency comparison"
 * DE 19701310B4: "Mode switching as such"
 * EP 1168120B1: "Block transmission of additional uncritical data"
 * Multi-cycle data (MCD) are no longer utilized in the position sensor system with BiSS
 * Because BiSS utilizes the PHY of SSI [(RS-422)], it develops as the successor of the SSI interface in automation