Abstract:

Currently the knitting machine of piezoelectric ceramic actuators are controlled with parallel bus network. This paper puts forward a needle selector control method of RS-485 based on high speed serial bus. At a baud rate of 4 M on the RS-485 bus, multiple digital needle selectors based on RS-485 bus are parallel. In order to achieve the communication between host and slaves, multi-node bus structure and bus arbitration is designed. The test results indicate that this method can solve the phenomenon of the parallel bus transmission disturbance when the speed is higher and the distance is longer. Also the phenomenon of some instabilities of needle selectors can be solved. This method meets the real-time requirements and improves the stability of digital needle selector.

Key words: circular weft knitting machine, RS-485 bus, bus arbitration mechanism, multi-node, digital selector