Programmable Logic Controllers (PLC) are often defined as miniature industrial computers that contain hardware and software used to perform control functions.
This manual describes the concepts behind programming PLC-3 family processors. Included in this manual is detailed information on how the PLC-3 programming instructions work.
Simplified Illustration of PLC Function in a SCADA System tographs of open SCADA PLC panels. The PLCs in the first photo appear in the center of the panel, while the PLCs in the second panel appea
The PLC Technician’s Handbook was developed to be a compact collection of fundamental content for practicing automation and PLC technicians to reference through their career.
A PLC (Programmable Logic Controller) is an industrial computer used for automation of electromechanical processes, such as control of machinery on factory assembly lines, amusement rides, or light fixtures.
Most real programmable logic control systems are a combination of continuous and discrete sensors and actuators. Actuators produce Finite quantities (batch) of materials . The input materials typically assume a defined order of processing actions.
Electrical continuity in an input circuit, occurs when there is a complete path for current to flow. When there is electrical continuity, a bit in the PLCs memory (sometimes called the input image table) is set to a 1. Note: It’s possible to have electrical continuity and not have logical continuity (and vise versa).
