Siemens SINUMERIK 840Di Function Manual page 875

Resetting of the emergency stop button or a signal derived directly from the button must be
routed to the controller (PLC) as a PLC input.
In the PLC user program, this PLC input must be forwarded to the NC to interface signal
DB10, DBX56.2 (acknowledge emergency stop).
Connection conditions
See the hardware configuration guide (Operator Components Manual) for information on
connecting the emergency stop button.
References:
/BH/ Operator Components Manual
2.3 Emergency stop sequence
2.3
EN 418 standard
After actuation of the emergency stop control element, the emergency stop device must
operate in the best possible way to prevent or minimize the danger.
"In the best possible way" means that the most favorable delay rate is selected and the
correct stop category (defined in EN 60204) can be determined according to a risk
assessment.
Emergency stop sequence
Sequence in the NC
The predefined (in EN 418) sequence of internal functions implemented to obtain the
emergency stop state is as follows in the control system:
1. Part program execution is interrupted.
2. The interface signal DB11, ... DBX6.3 (BAG ready for operation) is cleared.
3. The interface signal DB10, DBX106.1 (emergency stop active) is set.
4. Alarm: "3000 Emergency Stop" is displayed.
Emergency Stop (N2)
Function Manual, 08/2005 Edition, 6FC5397-0BP10-0BA0
All machine axes are braked within their respectively configured, axis-specific times:
MD36610 $MA_AX_EMERGENCY_STOP_TIME (braking ramp time for errors).
The maximum brake ramp that can be achieved is defined by the maximum brake current
of the respective drive. The maximum brake current is achieved by setting a setpoint = 0
(fast braking).
Detailed Description
2.3 Emergency stop sequence
2-3