Festo Контроллер двигателя CMMD-AS - Manual (Page 90)

4. Functional safety engineering
90 Festo P.BE-CMMD-AS-HW-EN 1002NH
4.3.3 Activation of SS1
The following steps show how you can bring a rotating drive into the "Safe standstill"
status:
1. Before the SS1 function is activated (i.e. driver supply relay "OFF" and end stage
enable "OFF"; both switch-off paths block the pulse-width modulation 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 parametrised using the
parametrising software ("Emergency stop braking acceleration").
2. After reaching a speed of 0, the drive is controlled at this setpoint for a parametrisable
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, SS1 can now be activated (switch off driver supply relay activation and
end stage enable 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 relay control signal
for switching off the driver supply, the feedback contact closes ([X3.1/2], pin 5 and 6).
6. At time t13, an "H" is displayed on the 7-segment display of the servo controller to
indicate a "Safe halt". This occurs at least 30 ms after the the potential-free
acknowledgment contact closes (t13 – t12).
4.3.4 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.