無協議通信在空調系統監控中的應用
Application of Non一protocolC ommunicationin S upervision of Air-conditioning System

摘要:MODBUS是用于控制設備的一種通用串行通信協議。簡要介紹MODBUS協議以及PL(:與變頻器之間進行無協議通信的方法;討論循環冗余校驗碼(CRC16)的生成方法，并設計PLC計算CRC16的子程序。給出了一臺歐姆龍小型PLC，使用RS-422A總線，通過無協議通信的方式集中監控空調系統多臺分散變頻器的工程實例。實際應用表明，該方法簡單易行、可靠性高、控制效果良好、經濟實用。
關鍵詞:無協議通信 變頻器 空調系統 監控 MODBUS協議
Abstract: MODBUS is a universal serial communication protocol used in controlling devices. The MODBUS protocol and the method of nonprotocol communication between PLC and inverter are introduced. The creation method of cyclic redundancy check code(CRC16)was discussed and the calculation subroutine of CRC16 by PLC was designed. An example of application that several distributed inverters in air-conditioningsystem monitored by one OMRON pocket PLC through non-protocol communication via RS-422A bus was given. The practice indicates that this method is convenient, reliable and economical.
Keywords:N on-protocolco mmunication Inverter Air-conditionings ystem Supervision MODBUS protol