Siemens TIA Safety : guard door

[aand74]

Our system has S7 1516 F CPU. We have doors that have contactless safety doorcontact that is cat 4 ple rated. The sensor provides us with two eqiuvalent safety outputs.
In our safety program we could used the function SFDoor. SFDoor is normally for two sensors on the door. If we use our current sensor in combination with SFDoor, we have no monitoring for discrepancy of the two signals from the sensor. So, is it better to use the EStop function block (that has capability of monitoring discrepancy)?
If we use one of our sensors on one door, what safety category do we reach then? Or, when is it necessary to use two physical sensors on a door?

 

[aand74]

No suggestions?

 

[L D[AR2P#0.0]]

A door normally has open and closed contacts so it can be in the intermediate position of not closed and not open, that is what SFDoor is for. Can you show schematicalyl how your door contacts operate?

 

[aand74]

It concerns a guard door that turns open, not a sliding door.
It only has a sensor that gets activated when the door is closed.
The sensor is a non-contact safety switch. It is an Euchner
CES-I-AR : https://www.euchner.de/en-us/products/transponder-coded-safety-switches-without-guard-locking/safety-switch-ces-ar/ces-i-ar-f-c04-sg-161679/#downloads-tab
It has two equivalent safety outputs, that give high output when the door is closed.

 

[L D[AR2P#0.0]]

Yes, I would use the Estop block for that application.

 

[aand74]

Is the reason to use the Estop block that the Estop block has discrepancy check (both contacts simultanous) and that SFDoor has that check not?

 

[L D[AR2P#0.0]]

No, it's because it is not a door in the sense that SFDoor requires.

 

[JesperMP]

The Euchner switch seems to be an all-in-one device that is not normally intended to be used with an external safety relay.
If you connect it with the safety PLC, then it is similar to cascading two safety relays.
The reset function for the door is in the switch. The safety function in the safety PLC must have auto-reset.