NEW GENERATION PROGRAMMING CONTROLLER - 2.
Many controllers advances in the programmable controllers are effectively ongoing today. These advances are not only the effect of the programmable controller design, but also the philosophical to control system architecture,changes include hardware ( physical components ) and software (control programmed upgrades. The following list describe some recent PLC hardware enhancement.
In using new advanced microprocessor and electronic technology faster scan time are being achieved.
-Faster scan time are being achieved using new advanced microprocessor and electronic technology.
-Small low cost PLCs which could replace four to ten relays,the new PLCs have more power than their predecessor, the simple relay replacer.
-High - density input and output i and o system provides space and efficient interface at low cost .
-Intelligent microprocessor based i and o interface have expanded distributed processing.Typical interfaces includes PID ( Proportional integral derivative),network ,CANbus, Fieldbus,ASCII,communication positioning,host computer and language modules (e.g:BASIC,PASCAL)..
-Mechanical design improvements have included rugged input and output enclosures and input and output systems that .have made the terminal an integral unit.
-Special interfaces have allowed certain devices to be connected directly to the controllers. Typical interfaces include thermo-couples,strain gauges and fast response inputs.
-Peripheral equipment has improved operator interface techniques,and system documentation is now a standard part of the systems.
  All of these hardware enhancements have led to the development of the programmable controller faimilies ,These family consist of a product line that ranges from very small microcontrollers with as few as 10 i and o points,to very large and sophisticated PLC,with as many as 800 i and o points and 128000 words of memory. These family member using common i and o systems and programming peripherals,could interface to a load communication network.The family concepts is an important cost saving development for users.