Hello,

If I have a PROFINET controlled G120C is it possible to connect an emergency stop mushroom to one of digital inputs and to OFF3 so I can Quick Stop the drive independently from the PLC, but still controll everything else via PROFINET ?

Hi, 

What do you think about this example?

SINAMICS G: Speed Control of a G120 (StartDrive) with S7-1200 (TIA Portal) via PROFINET/PROFIBUS DP with Safety Integrated (via Terminal) and HMI

If it does not fit your requirements, there are further examples here you may have a look:

SINAMICS Application Examples from Motion Control

Thanks for the link MicroMan, I saw it but thought it's only G120 related - seems I was wrong.

I'll analyze the example. But I was just thinking ... Having set all the control via PROFINET if I add/interconnect a DI to OFF3 wouldnt this work? 

I know it's kind of a stupid question but cant test it right now.

I once had a trigger via terminal connection for STO and SS1 from a safety PLC output and it worked fine. I never really looked if the strict requirements of SIL levels are accomplished, but the motor did stop in a controlled manner according to OFF3 ramp when I triggered the SS1 function. But is your PLC an F-PLC?It should work also without a safety PLC but without really satisfying the SIL requirements

Yes there is.  Download the G120 Safety Integrated Manual (they all work the same way).  I don't have a direct link, Google is your friend.

If you set the STO Delay Timer to a time similar to your deceleration time, you will get the SS1 OFF3 (controlled stop) until the timer expires, then you will get an STO (pulse disable).  No need for F-PLC and you have a safe stop.

Jeff Casagrande

OFF3 by standard DI is not safe for Emergency Stop and may not satisfy regulations for emergency stopping.  STO is the safest.

Using only OFF3 is not enough, but according to ISO 13850 you can achieve Stop category 1 either using SS1 funtion (certified) - if there is one, or first apply OFF3 to stop movements and then remove electrical power i.e. by using certified STO function which is available more often.

It should be sufficient to meet the safety requirements. The are many dacuments about safety saying that it is what people do to stop load with high inertia. It is also how we stop our machines.