PLC Advantage and why its become very popular

A PLC or programmable logic controller is a computer based solid state device that controls industrial equipment and processes. It was initially designed to perform the logic functions executed by relays, drum switches and mechanical timer/counters. Analog control is now a standard part of the PLC operation as well.

The advantage of a PLC over the RTU offerings from various manufacturers is that it can be used in a general-purpose role and can easily be set up for a variety of different functions.

The actual construction of a PLC can vary widely and does not necessarily differ much from generalizing on the discussion of the standard RTU. PLCs are popular for the following reasons:

• Economic solution
PLCs are a more economic solution than a hardwired relay solution manufactured RTU

• Versatility and flexibility
PLCs can easily have their logic or hardware modified to cope with modified requirements for control

• Ease of design and installation
PLCs have made the design and installation of SCADA systems easier because of the emphasis on software

• More reliable
When correctly installed, PLCs are a far more reliable solution than a traditional hardwired relay solution or short run manufactured RTUs.

• Sophisticated control
PLCs allow for far more sophisticated control (mainly due to the software capability) than RTUs.

• Physically compact
PLCs take up far less space than alternative solutions.

• Easier troubleshooting and diagnostics
Software and clear cut reporting of problems allows easy and swift diagnosis of hardware/firmware/software problems on the system as well as identifying problems with the process and automation system.