
Safety engineering
Device modules
Function mode of the safety modules
16
EDS94AYAF EN 1.0
1.2.2
Function mode of the safety modules
Disconnecting paths
The transmission of the pulse width modulation is safely disconnected by the safety
module. Hence the drivers do not create a rotating field. The motor is safely switched to
torqueless operation (STO).
M
SMx
PWM
µC
P
C
3x
3x
Xx
SSP94SM320
Fig. 1−1
Disconnecting paths of the safety modules
SMx
Safety module
xx
Input / output terminal
C
Control section
m
C
Microcontroller
PWM
Pulse width modulation
P
Power section
M
Motor
Safety status
When the controller is switched off by the safety module, the controller switches to the
"Safe torque off"device state.
ƒ
"Controller in STO state" is entered into the logbook (0x00750003).
ƒ
"Safe torque off active" is displayed in C00183.
Fail−safe status
Note!
If internal errors of the safety modules are detected, the motor is safely
switched to torque−free operation (fail−safe status).