1. Lower prices, smaller dimensions
You may feel that there is a tendency in the PLC offering, that prices decrease and sizes become more compact. It is mainly connected with the development of quasi-conductor technology, that allows ensuring of the same solution with less number of components and with more compact sizes.
2. Operator panels — PCs'
More and more frequent, computerized process visualization programs SCADA are used for the automation of production processes Visualization program also performs operator panel functions and in that case, there decrease the need to use specialized PLC operator panels.
3. PLC + PC — new approach in the process control
Continually increasing complex application, changes approach to the process control and management. By basing on PC created options and provided information as well as friendly Windows interface, operator is actively involved in the process control improvement (quite frequently without even knowing that).
4. Improvement of communications > simplification
Producers of PLC and other industrial components spend more resources to ensure connectivity of the devices, ie. develop communication protocols. It would be easier if several unified standards could be introduced, however that will not happen. In the same time, each producer will look forward to ensure, that his produced industrial devices allow more communication. In that way, forms a tendency that protocols of different companies become similar, more available, and as a result, in the future, a tendency towards decrease of the used protocols number can develop.
Among the most common communication protocols there should be named — Device Net, Profibus, Modbus and Ethernet. Methods how to connect products of different companies are also developing. For example, OPC servers are used in order to connect PLC of one company with visualization program of another company. In that way producers of the industrial components are forced to think of the user, as in the opposite case, due to the limited communication opportunities, given industrial product could remain unmarketable.