Sto – Safe Torque Off - Festo CAMC-G-S3 Manual

2 Product description of safety module CAMC-G-S3
2.5.1 STO – Safe Torque Off
Application
The function described here implements the safety function STO according to EN
61800-5-2 (stop category 0 from EN 60204-1).
Use the "Safe torque off " function (STO) whenever you have to reliably disconnect the
energy supply to the motor in your particular application but there are no additional
requests for targeted stopping of the drive.
The STO function is activated by the factory setting (advance parameterisation).
As the function is used by other functions (request through SS1 or error reaction on viola­
tion of other requested safety functions), it cannot be deselected.
Function
The function "Safe torque off " switches off the driver supply for the power semiconductor, thus pre­
venting the power end stage from supplying the energy required by the motor.
The power supply to the drive is reliably disconnected via the active safety function STO "Safe Torque
Off ". The drive cannot generate torque and so cannot make any hazardous movements. With suspen­
ded loads or other external forces, additional measures must be taken to ensure that the load does not
drop (e.g. mechanical clamping units). In the STO "Safe torque off " status, the idle position is not mon­
itored.
The machine must be stopped and locked in a safe manner. This especially applies to vertical axles
without automatic locking mechanisms, clamping units or counterbalancing.
Please note
There is a risk that the drive will advance if there are multiple errors in the
CMMP-AS-...-M3.
Failure of the motor controller output phase during STO status (simultaneous short
circuit of 2 power semiconductors in different phases) may result in a limited detent
movement of the rotor. The rotation angle / path corresponds to a pole pitch. Examples:
– Rotary axle, synchronous machine, 8-pin è movement  45° at the motor shaft.
– Linear motor, pole pitch 20 mm è movement  20 mm at the moving part.
The STO (Safe Torque Off ) function does not provide protection from electric shock, only
from hazardous movements! The drive is not disconnected from the power supply as is
required for electrical safety è hardware description, GDCP-CMMP-M3-HW-...
66 Festo – GDCP-CAMC-G-S3-EN – 1406NH – English