BiSS interface

BiSS Interface Logo

The open source BiSS Interface (bidirectional/serial/synchronous) is based on a protocol which implements a real time interface. It enables a digital, serial and secure communication between controller, sensor and actuator. The BiSS protocol is designed in B mode and C mode (continuous 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; competing solutions are the proprietary standards of Hiperface and EnDat.

Application

• Position sensor system
  • Rotary encoder (absolute encoder) ^[1]
  • Linear position sensors (absolute encoder) ^[2][3]
• Drive control (motor feedback) ^[4][5]
• Intelligent sensor system (smart sensors) ^[6]
• Robotics ^[7]

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. 10 MHz, 1 km, LVDS 100 Mbit/s
• Independent of the applied physical layer
• CRC secured communication (sensor data and control data secured separately) ^[8]

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) ^[9]

History of BiSS in position sensor system

• BiSS was showcased in 2002 by its founders iC-Haus GmbH ^[10]
• 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

External links

• BiSS Interface Website
• BiSS C protocol description (PDF, 964 kB)

References