HEIDENHAIN MANUALplus 620 Technical Manual page 985

Automatic test of
the motor brake
January 2012
Settings in the configuration editor
Axes
ParameterSets
[Key name of the parameter set]
CfgServoMotor
testBrakeCurrent
testBrakeTolerance
You can carry out an automated functional test of the motor brake after
switching on the drive, either before traversing the reference mark or through
activation by PLC Module 9143.
This brake test only functions in combination with HEIDENHAIN inverter
systems and only when using the brake output on X392/X393/X394 if it is
wired according to the basic circuit diagram from HEIDENHAIN.
For the period of one second, a torque (current) is applied while the brake is
active. The path that the axis has moved is then measured. If the permissible
path is exceeded, the error message 8130 Motor brake defective <axis>
appears, and the axis remains controlled. The test is carried out
simultaneously for all affected axes.
Warning
In case of an error, the axis must be moved to a safe position, and physically
supported, if necessary. Only then may the machine be switched off so
that the defect can be corrected.
The brake test is activated (insert optional parameter) or deactivated (delete
optional parameter) separately for each servo drive via
MP_testBrakeCurrent. An additional test torque is applied to the servo drive
during the brake test. This test torque is defined via a multiplier for the motor
stall current I0. MP_testBrakeCurrent defines the multiplier. This test torque
exerts additional load on the holding brake of the servo drive. The axis is
prevented from moving during the brake test and the brake test is considered
to have been passed only if the brake withstands this load.
The control determines the algebraic sign of the test torque individually for
each servo drive depending on the holding torque.
If no motor current flows while testing the motor brakes, the error message
8140 No current for brake test <axis> appears.

Enter in MP_testBrakeCurrent a factor for the motor stall current with
which the motor brake test is to be carried out. If the test is not to be carried
out, or for motors without brakes, delete the parameter from the
configuration.
The reference value for the factor from MP_testBrakeCurrent is the stall
current I0 entered in the motor table. If I0 in the motor table equals 0, then
the rated current I-N from the motor table is used.
6.17 Monitoring Functions
MP number
401323
401324
985