PLC and SCADA Systems

PLC programs are typically written in a special application on a personal computer, it then downloaded by a direct-connection cable or over a network to the PLC. The program is stored in the PLC either in battery-backed-up RAM or some other non-volatile flash memory.

While the fundamental concepts of PLC programming are common to all manufacturers, differences in I/O addressing, memory organization and instruction sets mean that PLC programs are never perfectly interchangeable between different makers. Even within the same product line of a single manufacturer, different models may not be directly compatible.

PLCs are well-adapted to a range of automation tasks. These are typically industrial processes in manufacturing where the cost of developing and maintaining the automation system is high relative to the total cost of the automation, and where changes to the system would be expected during its operational life.

SCADA systems are used for communication between software systems and the machines they control. The old monolithic SCADA systems are being replaced by open, distributed environments, which provide a central overview of the whole system. Open protocols and network technology are applied to reduce costs while increasing quality and reliability of the system.

SCADA systems are used for communication between software systems and the machines they control. The old monolithic SCADA systems are being replaced by open, distributed environments, which provide a central overview of the whole system. Open protocols and network technology are applied to reduce costs while increasing quality and reliability of the system.