一种基于现场总线的计算机分级控制系统

A Computer Hierarchical Controlling System Based on Fieldbus

介绍一种PC和模块化嵌入式控制器构成的分级电火花加工用计算机控制系统。用PC实现图形化人机交互,并按规则进行决策产生控制指令。嵌入式主控制器接收并解释PC的指令,协调各嵌入式功能单元完成控制操作,通过RS232接口与PC进行连接,通过RS485总线与其它功能单元构成主从式控制网络,使用MODBUS协议传送信息。并使用脉冲持续时间内平均电压检测法进行间隙状态检测,避免了脉冲参数变化对间隙检测的影响,提高了间隙控制的稳定性。经测试,控制系统可满足电火花加工的要求。

A computer controlling system of a hierarchical EDM is introduced which is composed of PC and module embedded controller,that realizes figure human-computer interaction with PC, carries on decision and produces the order of controlling according to the rule. The embedded master controller receives and ex- plains the orders of PC, coordinating every embedded function units and finishing controlling operation , which is connected with the PC used RS232 inferce and constitutes a master-slave network used the RS485 bus with the implementation of the various functional units using the MODBUS protocol to convey information. A kind of average voltage measuring method in pulse duration is used to gap state investigation, avoiding the influence that the parameter change of the pulse to the gap investigation, which has improved stability of the gap state controlling. Through testing , the request of control system of EDM is satisfied.