Basics of BiSS-C technology

The EL5042 support the unidirectional BiSS-C communication. The transmission of the data is triggered by the master clock. The end of data transmission is identified with the timeout. A typical communication process is following:

1. Idle state: master clock is high and the BiSS-C slave indicates his ready state also with high value.
2. With the first rising edge of the master clock the synchronous position acquisition is started.
3. After the second rising edge of master clock, the slave responds with a low value “Ack” period.
4. After the “Ack” period is completed, the slave generates a “start” bit, which is always followed by a “0” bit. The position data is transferred with the 2nd bit after the start bit, according to the data format of the slave. The communication is synchronized with the master clock. The status bits “Error” and “Warning” and the CRC are transmitted after the position data.
5. The communication ends with the BiSS timeout. No further pulses are send to the slave, master clock set the line to the idle state “1”. After the timeout is expired and the slave is ready to transmit new position data, the slave line goes also to the idle state “1”. The communication starts again.