Controlling The Motor Brakes - HEIDENHAIN iTNC 530 Service Manual

3.3.12 Controlling the motor brakes

The motor brakes are controlled with the BRK braking signal, which is transmitted to the
HEIDENHAIN inverters via the PWM interface (X51 to X62). The corresponding outputs are
activated there. See the basic circuit diagrams.
Control of the motor brakes via the PWM interface must be deactivated for non-HEIDENHAIN
inverters that do not support this function:
The motor brakes are opened no later than 50 ms after the speed controller is switched on. For
safety reasons, the controller is not switched off until the braking signal has been output.
If the inverter sends the RES.PS reset signal, then the BRK braking signals are output
immediately upon switch-off of the controllers, i.e. without any overlap time.
Activated brakes cause a change in the controlled system. The motor with the changed
controlled system is controlled during the overlap time. This can lead to oscillations when the
controller is switched off. These oscillations are suppressed by the NC software. MP2220 bit 3
can be used to deactivate the suppression of vibrations. HEIDENHAIN does not recommend
switching off the suppression of the oscillations.
In MP2309.x you can define a time period in which the speed and position controller parameters
are adjusted to values for controlling a closed brake when the drive is switched on. This
parameter can be used to avoid oscillations in the drive during switch-on when the brake is still
closed and the controller is already active.
MP2220
Input:
MP2234
Format:
Input:
MP2308.x
Input:
MP2309.x
Input:
3 – 684
MP2234.x bit 0 = 1
Enter in MP2308.x the time (overlap time) after which the controller is to be switched off after
the braking signal has been output.
Monitoring functions
Bit3 - Switching off the controller when the motor brakes are activated
0: Suppress oscillations
1: Vibrations are allowed
Internal triggering of the motor brakes via the PWM interface
%xx
Bit 0
0: Signal is transmitted
1: Signal is not transmitted
Bit 1– reserved
Time between output of the braking signal BRK and switching off of the
controller (overlap time)
0.001 to 0.500 [s]
0: 0.200 s
Controller parameters adjusted to closed brake
0: Previous behavior; not active
0.001 to 1.999 [s]
HEIDENHAIN Service Manual iTNC 530