Festo Контроллеры двигателя CMMS-ST - Manual (Page 91)

4. Functional safety engineering
Festo.P.BE-CMMS-ST-G2-HW-EN 1008NH 91
4.3.4 Activation of “Safe Stop 1”
The following steps show how you can bring a rotating drive into the ”Safe standstill”
state:
1. Before ”Safe torque off” is activated (i.e. the driver supply relay ”OFF” and the end
stage enable ”OFF”; both switch-off paths block the PWM signals), the drive should be
brought to a standstill by removing the controller enable. Depending on the
application, the braking ramp (t9-t8) can be parameterized using the parameterizing
software (”Emergency stop braking acceleration”).
2. After reaching a speed of 0, the drive is controlled at this setpoint for a
parameterisable switch-off delay time (t10-t9). This adjustable time is the delay
required to apply the motor holding brake. This time depends on the holding brake
used and must be parameterised by the user. For applications without a holding
brake, this time can be set to 0.
3. After this time, the internal end stage enable is switched off by the microprocessor
(t10).
The holding brake is always applied when the ”braking ramp time +
set switch-off delay“ has expired, even when the drive has not
come to a stop within this time.
4. From time t10, the "Safe torque off" can now be activated (driver supply relay and end
stage enable switched off at the same time). Time (t11-t10) depends on the
application and must be defined by the user.
5. When the driver supply relay control signal is removed (t11) the capacitors in this
circuit area discharge. Approx 80 ms (t12-t11) after removing the driver supply relay
control signal the feedback contact closes ([X3], Pin 5 and 6).
At time t13, an ”H“ is displayed on the 7-segment display of the controller to indicate a
”Safe standstill“. This occurs at least 30 ms after the potential-free feedback contact
closes (t13-t12).
4.3.5 Setting the switch-off delay
The switch-off delay of the holding brake must be set in the FCT. The set time is necessary,
as the brake does not close immediately due to the mechanical design. If this set time =
0 or <= 10 ms, the vertically hanging load can briefly slip through.