seth350
Member
I have a project coming up that will need zoning and additional functionality added in the future. I wanted to get into distributed safety where a safety device could be added easily without having to branch into the main safety circuit.
I am having a hard time wrapping my head around the use and physical connections between safe outputs and field actuators. The system in question would be a B&R Safety PLC with digital I/O cards. It’s uses PLCopen Safety function blocks.
What I do know about the B&R platform is that there are two controllers. The main PLC which would take care of controlling the equipment and separately the Safe PLC which only monitors and reacts to safety events as instructed in its programming.
In a typical and simple world, you will have an estop, mcr/safety relay, and reset button. The mcr will remove power to all actuators and remove power to the output cards.
When using a Safe PLC with I/O, would you still need an MCR/Safety Relay?
Are the actuators controlled from the safe output card or is the output card just a glorified “safe” power supply?
As in, a safe output would actually power an output card?
It seems to me that a safety relay would still be needed to act as an interposing relay.
I am having a hard time wrapping my head around the use and physical connections between safe outputs and field actuators. The system in question would be a B&R Safety PLC with digital I/O cards. It’s uses PLCopen Safety function blocks.
What I do know about the B&R platform is that there are two controllers. The main PLC which would take care of controlling the equipment and separately the Safe PLC which only monitors and reacts to safety events as instructed in its programming.
In a typical and simple world, you will have an estop, mcr/safety relay, and reset button. The mcr will remove power to all actuators and remove power to the output cards.
When using a Safe PLC with I/O, would you still need an MCR/Safety Relay?
Are the actuators controlled from the safe output card or is the output card just a glorified “safe” power supply?
As in, a safe output would actually power an output card?
It seems to me that a safety relay would still be needed to act as an interposing relay.