Several ways of connecting upper computer and MES

Preface

In practical application , Students often ask ： How does the upper computer communicate with MES Information exchange ？

Today I would like to introduce , The upper computer and MES Several common ways of docking .

database

Database is a skill that any developer must master , therefore , For some simple interactions , It should be acceptable to both parties through the database , Pay attention here , Try to avoid handling production data sheets , According to the actual business scenario , By adding a data table dedicated to interaction , To reduce operational errors .

file

sometimes , The upper computer can also communicate with... Through files MES Interaction , It can be files in various formats , text file 、excel、xml Fine . such as , Host computer or MES Generate text files regularly , The generation time of the other party's detection file , To determine whether the process is completed , Then realize the follow-up process .

Transport layer TCP

there TCP Refers to the transport layer TCP, Both parties have agreed on the contents of the agreement , adopt Socket Connect , Send and receive , To achieve data communication .

application layer TCP

application layer TCP Including some defined application layer protocols , such as ModbusTCP、MQTT、OPCUA etc. .

KepServer

There are developers from some manufacturers , For convenience , Will use KepServer To do data interaction ,KepServer You can not only walk OPC, It also supports databases or Iot Gateway Plug-ins and other methods .

WebService

WebService It's a SOA（ Service oriented programming ） The architecture of , It is not dependent on language , It doesn't depend on the platform , Different languages can be implemented （ adopt xml describe ） Call each other between , adopt Internet Based on Http The interaction between network applications of the protocol . adopt SOAP stay Web Software services provided on , Use WSDL The document explains , And pass UDDI To register .

WebApi

WebApi Is a simple build HTTP A new framework for services . stay .Net On the platform WebApi It's an open source 、 ideal 、 structure REST-ful Service Technology , Can be deployed in applications and IIS On .

Of course , We can also pass Http Protocol to achieve docking , After all WebApi The essence of Http agreement .

WCF

WCF Is based on SOAP Of , The data format is XML,WCF yes Web Service（ASMX） The evolution of , Can support a variety of protocols , image TCP,HTTP,HTTPS,Named Pipes, MSMQ. however WCF The main problem is , It's very complicated to configure , therefore WCF Less and less used .