Function And Application; Circuitry Of The Control Inputs - Festo CMMO-ST-C5-1-LKP Manual

Function and application

3 Function and application
The STO function "Safe Torque Off " ("Safe Torque Off") enables 2-channel, secure disconnection
of the power supply for the motor that is connected to the motor controller. The safety function is
requested solely via the control inputs of the STO connection [X3] on the motor controller. Safety-ori-
ented circuitry for additional interfaces of the motor controller is not required.
Fig. 1: "Safe Torque off" (STO) connection
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[X3] STO
3.1

Circuitry of the control inputs

To protect against unintended start-up, the motor controller must be activated via the connection [X3]
with the category required for the application according to EN ISO 13849-1. Achievable safety level of
the STO function è 2.1.3 Safety characteristics.
The following components for requesting the STO function can be connected to the control inputs
(è 4.1 Installation):
– safe semiconductor outputs (electronic safety relay units, active safety sensors, e.g. light curtains
with OSSD signals) (OSSD = Output Signal Switching Device)
– Switch contacts (safety relay units with relay outputs, passive safety sensors, e.g. forced position
switches)
Festo — CMMO-ST-C5-1-LKP — 2022-05b
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