Automation, now a days have become in integral part of the industry, say any production as well as process industry, it is progressively increasing the productivity and the profitability of most large organization by rapidly becoming more efficient and competitive by their methods of production and management. Small industries with small exceptions, is not progressing to the same extended and their profitability is far too low for stability and growth.
The efficiency of small industries is however, of vital importance to the economy of the country. They represent 90% of all industries, employ about half of those engaged in large industries and produce nearly half of the manufactured goods.
It can control the overall action of the system in the field plant. It examines the status of the input and in responses control the overall process through the output. Combination of the input and output data are referred to as logic. Several logic combinations are usually required to carry out program. This program is stored in the memory and is periodically changed as per the requirements of the party by an order given to an operator, usually run the programs in predetermined order for SCADA.