PLC is an unavoidable control system used in the process industry. The PLC architecture is modular and flexible, allowing the expansion of hardware and software elements as the application needs change.
A PLC system offers many advantages from reliability and repeatability to programmability to control solutions.
The advantages obtained with programmable controllers improve with the person using them, the more you know about PLCs, the more you can solve other control problems.
Below listed some simple advantages of PLC system:
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High reliability
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Minimal space requirements
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Flexible control
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Higher level of performance
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Multifunctional capability
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Reduce hardware/wiring cost
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Reduce space requirements
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Installation flexibility
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Controls a variety of devices
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Eliminate long wire/conduit runs
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Reduce troubleshooting time
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Service without wiring
1. Programmability:
The programmable feature offers the single greatest gain for programmable controller use and implementation. The first step in implementing a modular control system is the removal of hardwired control in favour of programmable control.
When mounted, the control plan can be manually or automatically adjusted by modifying the field wiring to satisfy the regular control specifications. This simple change is possible because there are no physical links between the input devices and output devices in the field, as in hardwired systems.
2. Ease of installation:
Several attributes make installing PLCs easy and cost-effective. The relatively small size makes it possible to place a PLC conveniently in less than half the space required by an equivalent relay control panel.
Several attributes make installing PLCs easy and cost-effective. The relatively small size makes it possible to place a PLC conveniently in less than half the space required by an equivalent relay control panel.
Remote input/output stations are installed in optimal positions in large installations. The remote station is connected to the CPU by a coaxial cable or twisted pair of wires. This configuration leads to a significant reduction in material and labour costs compared with a hardwired system.
3. Ease of maintenance and troubleshooting:
Maintenance is limited to replacing modular plug-in modules with nearly all parts being solid-state. Included in each major component, fault detection circuits and diagnostic indications suggest whether the device is functioning properly or not.
Any programmed logic can be viewed to see if inputs or outputs are ON or OFF using the programming device. It is also possible to write programmed instructions to enunciate certain failings.
These and a couple of other PLC attributes make it a valuable part of any control system. Once installed, their contribution will be noticed quickly and payback will be readily realized