PLC Skills are vital for the Maintenance Engineer These are very high value skills.
Until the 1980s, electrical controls for automated machinery were based on relay logic where lots of relays and often timers and counters were hardwired together in a big control panel to create the sequence control for the machine.
This heavy reliance on electromechanical switching devices and the many hundreds of wire terminations invariably resulted in maintenance and reliability problems over a period of time.
So, when even basic PLCs came along, the electrical reliability of machinery improved dramatically because all of the old relay logic was taken over by a CPU which of course has no moving parts. Not only that, the PLC system could be programmed by a maintenance electrician because the PLC program was represented in a format the electrician was already quite familiar with ..... The Ladder Diagram.
Today, the PLC incorporates a staggering range of control features, it can be connected to data networks and interfaced with other automation control devices.
Many programs incorporate Data Values stored in a menu to create control of the logic and plant processes. So, it’s vital to be able to View these data values in real time as the machine is sequencing, otherwise, it could be argued, effective fault finding might not be possible.
With just a few days’ training, it’s possible to gain the valuable skills needed to interrogate the PLC program online for fault finding on automated plant and machinery.
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