B&R Safety block SF_GuardLocking_V1_00 question

[Patrick_Pennarts]

Dear all,

I have an issue with a BR safety block that we are currently using. Let me explain:

We currently have two types of machines with both different hardware; one is a demo prototype which has a SLX842 safety module, the other one which will be the final machine only has a SLX410. The 842 safety module has outputs, the 410 only has inputs. For the safety door on our machine we use SF_GuardLocking_v1_00 block in safedesigner.

We only have one input that will tell us the machine is closed&locked, so we use it on both s_GuardMonitoring and s_GuardLock and that works perfectly.

On the demo machine we can use an inverted SM1_PhysicalStateOutput01 to connect to our s_SafetyActive. So if the output is not high (which is the STO), it will be safe to open the door.

However, on the demo machine we don’t have outputs, so also no PhysicalStateOutput01 to connect here. So what to connect to the s_SafetyActive input? Is this normally a signal received from the normal “Grey” PLC? such as a Off status from your state machine?

[marcusbnr (Marcus Mangel)]

Hi Patrick,

From reading the documentation for this function block, my understanding is that the SafetyActive input is an acknowledgement that any safety hazards have been eliminated:

What this actually means in the context of your machine will depend on how your machine functions. Connecting a signal from the “grey” PLC is an option here, as is using another variable that’s set somewhere else in your safety program.

Of course, this answer comes with the caveat that it is up to you to set this in a way that makes the machine actually safe to use, and that part is up to you