Safety PLCs
Programmable Logic Controllers (PLCs) are computer control systems that detect the state of all input devices connected to it, make a decision based on a user-created program and then, output commands to any devices connected to it. PLCs monitor, control and communicate automated processes and act as the physical interface between devices and a SCADA or HMI system. PLCs are best suited for simpler processes and smaller automation projects that do not require rapid scalability. They are ideal for both simple and high-speed machine control and can be found in assembly equipment, motion control and dispensing systems.
Safety PLCs support all of the applications controlled by a standard PLC, while also integrating safety functions designed specifically for the control of safety-related systems. Safety PLCs must not fail, however, if failure cannot be avoided, it should happen in a safe and predictable way. This is achieved through redundant microprocessors. These standby processors are used as a backup, eliminating the need for safety relays. Safety PLCs also have built-in diagnostics that allow for continuous monitoring of the various inputs and outputs. When a fault is detected, alerts and information can be presented by HMI or web server to inform operators of the equipment status. This helps to locate the fault and enable a quick resolution. Safety PLCs are an ideal choice for complex machines or automation lines requiring protection for both the operator and the machine.
