Haiwellbus Protocol is a Protocol defined by Haiwell Co. for data transferring between Haiwell PLCs. It is using RS485 CAN structure, so it can transfer both discrete data and contiguous data. It is faster and moreefficient . It can maximum acomplish 30 datas interactions in one communication. When the Single PLC is not encough to control the devices orthe devices are widely distributed .More PLCs are needed to control distributedly.
Haiwell PLC has powerful networking capability. The Haiwell PLCs can not only communicate byHaiwellbus protocol , but also by standard Modbus Protocol. Whatever protocolis used,the salve plc doesn’t need to write any program.Only need to do write a programm in the master PLC.Haiwellbus Protocol has two communication instructions ,HWRD( Haiwellbus reading instruction, need to define “Haiwell bus readingcommunication table”) and HWWR (Haiwellbus writing instruction , need to define“Haiwell bus writing communication table”). Here are the picture:
Suppose No.1 PLC read the data X0/M12/M300/M301/V100/V120/Y6 from No.2 PLC,and put it in native M500/M501/M502/M503/V600/V601/M800 of No.1 PLC .We definea name “read No.2 PLC” in Haiwell bus reading commucation table.:
Suppose No.1 PLC wants to write the native data fromM200/M301/Y2/AQ2/V10/V51/M800 to the No.3 PLC’s Y0/Y1/M300/V1/V10/V12/Y6 ,wedefine that name“write No.3 PLC ”in “Haiwellbus writing communication table” asfollows:
Haiwellbus Protocol’s communication programming is simple. Toacomplish the data transferring between Haiwell PLCs, it only needs 2instructions.