HEIDENHAIN MANUALplus 620 Technical Manual page 881

January 2012
You can determine by PLC which axes are switched off in 200 ms:
 Call Module 9159. The drive motors that are switched off are returned in bit
code.
Note
The bit-encoded status signal supplied by Module 9159 is a request to lock
the brake/clamping of the servo drive. Do not use the signal as a request to
switch off the drive concerned.
The following logic diagram shows the status signals of the PLC modules
9159 and 9162 as well as the trigger signal for the brake from the
HEIDENHAIN inverter.
A switch-on procedure with a test of the motor brake and a switch-off
procedure with an overlap time of 200 ms are recorded:
The logic diagram shows that the trigger signal for the motor brake can be
calculated from the status signals of the Modules 9159 and 9162:
Brake is not active = Status signal of Module 9162 AND NOT status signal of
Module 9159
This enables you to use the PLC to apply the test of the motor brakes to non-
HEIDENHAIN power modules, too.
The status of the drive controller is shown in NN_AxDriveOn. Use Module
9157 to inquire whether the drive controller is ready to be switched on.
6.16 The Control Loop 881