Application Of Programmable Logic Controller And Its Network In The Auto Latch Product Line

PLC (Programmable Logic Controller) is the new type of automationcontrol system. The technology of Relay control, computer control andcommunication control are integrated to PLC and it is designed to industrialcontrol. Since PLC has many advantages such as good usableness, goodpracticability, complete hardware, easy to program, etc, it has already usedwidely in all kinds of automation control.Rockwell SLC500^TM serials PLC is a minitype of Rack LogicController, including digital, analog, special I/O module and relativeperipheral equipment. The controller of SLC 500 has strong managementability, it could be selected and configurated flexibly for communicatonnetwork, function module and memory capability. The controller installeddifferent communication port coud provide muti-network to select such asEthernet, DH+ and DH485 network.This paper is focused on application of SLC500TM serials PLC andDH485 network in the Auto Latch Line. DH485 network can monitorprocedure parameter, devise parameter, equipment status, process status andapplication program in order to support data collection, data monitor,program upload/download and inspection control. VisualBasic is theObjected Oriented programme language. Application program is beendesigned and it used to achieve serial communication bwtween PLC and PC,which all of controller connected to DH485 network could be communicatewith PC. By some examples to analyse program, we know how to completethese function.