How to develop and maintain P.L.C logic controller?

Selection of PLC is depends on the requirements of the clients and the logic needs to be developed.prior to logic development concept of control required will be drafted as control philosophy, withrespect to control philosophy logic will be developed and uploaded to the PLC. then varify the logics by simulating and assure the logic built is perfect as per control philosophy.Once program is commssioned on the machine, demonstrate the functional checks of each and every control to client's representative.Generally no maintenance required for PLC unless logic needs to be modified.There are many popular brands in market like prosafe of YOKOGAWA, HIMA PLC, Siemens, ABB Delta V of EMERSON etc.     

First you have to select which PLC you are going to use.It will dependable according to the function of the Project and the cost. Most of the PLC development softwares have simulation within it .That means you can test the functonality of the program. Once the program is veerified and commissioned on the plant or machine you dont have to worry about the maintainence from PLC side. Popular brands Plc like Siemens,ABB,Rockwell,Mitsubishi have very very less chance to have maintenance issue. Once you installed it can run many many years without creating a problem.

Use simulators such as STEP7

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