I've ready through the the previous posts, and we've worked with safety design for a long time.
In the past, we worked with Pilz directly, and they stated to us that if we drove an expansion relay (with K1 & K2) from a single safety output, with feed back of the relay into the safety PLC, that we would achieve Category 3. Most of the rockwell literature states that a single output to a single safety contactor only achieves Cat 2. But it also doesn't show feedback of the contactor to a safety input.
It's been debated in our office, and bottom line is we can find no documents or literature anywhere that states a Category 3 rating for this circuit. Is this open to interpretation or is there some hard evidence?
Most systems in automotive are Category 3 (PLd) at best. Rockwell L80 Safety Partner is required to get to PLe, but we all know that a system is only as good as it's weakest rated device/circuit. But customers want the safety partner regardless of the PLd rating. General discussion here, would be great to get some feedback with some reference material to share! Thank you all!
Chris.
In the past, we worked with Pilz directly, and they stated to us that if we drove an expansion relay (with K1 & K2) from a single safety output, with feed back of the relay into the safety PLC, that we would achieve Category 3. Most of the rockwell literature states that a single output to a single safety contactor only achieves Cat 2. But it also doesn't show feedback of the contactor to a safety input.
It's been debated in our office, and bottom line is we can find no documents or literature anywhere that states a Category 3 rating for this circuit. Is this open to interpretation or is there some hard evidence?
Most systems in automotive are Category 3 (PLd) at best. Rockwell L80 Safety Partner is required to get to PLe, but we all know that a system is only as good as it's weakest rated device/circuit. But customers want the safety partner regardless of the PLd rating. General discussion here, would be great to get some feedback with some reference material to share! Thank you all!
Chris.