The Quantum Safety PLC is a system of safety related certified according to IEC 61508 by TUV Rheinland Group. This is based on the Quantum family of PLCs (Programmable Logic Controllers). For programming, the unity Pro XLS software programming of Schneider Electric must be used. Unity Pro XLS provides the all functionality of Unity Pro XL and is able to program additionally the Quantum Safety PLC.
The IEC 61508 is a technical standard that concerning to the Functional Safety of electronic, electrical, and programmable electronic Safety Related Systems. A Safety Related System is a system that is required to perform 1 or more specific functions to ensure the risks are kept a an acceptable level. Such functions are defined as a Safety Function.
A system is defined safe functionally if systematic, random, and common cause failures do not lead to malfunctioning of the system and do not result in injury or death of humans, loss equipment and production and spills to environment.
Safety Functions are executed to achieve and maintain a system of Safe state. The IEC 61508 specifies the Safety performance in 4 levels for a Safety Function. These are called SIL (Safety Integrity Level), ranging from 1, the lowest, to 4, the highest. The Quantum Safety PLC is certified to use in SIL 2 applications in which the de-energized state is the Safe state, for instance in an Emergency Shutdown (ESD) system.
You can also use the Schneider Electric Safety product for creating a HSBY (Hot Standby) solution if you require high availability for a Safety Related System. The Quantum Safety PLC consists of Safety modules which are allowed to perform Safety Functions. However, it also supports called non interfering modules, thereby enabling you to add non safety parts at your SIL 2 projects. Therefore, the products of Schneider Electric must be distinguished into:
• Safety modules
• Non interfering modules.