How do I avoid getting a safety card error when sending a fault reset command while the safety door is open?

Sending a fault reset command (CLRFAULT) while the safety door is open can generate a safety card error. 

CLRFAULT restarts the safety card.

The start conditions are not correct in this situation because the safety door is open. Send the CLRFAULT only if the start conditions of the machine are correct, i.e. the safety door is closed.