2 Description of the safety function STO
22 Festo – GDCP-CMMS-AS-G2-S1-EN – 1306NH – English
With use of the PNOZ s5 from Pilz, two-channel operation with cross-circuiting recognition is possible.
This permits recognition of:
– earth faults in the star t and input c ircuit.
– short circuits in the input circuit / start circuit.
– cross circuits in the input circuit.
Warning
The motor holding bra ke, supplied as a standard feature, or an ex ternal moto r holding
brake controlled by the motor controller, is not appropriate for personal protection!
• Also secure vertical axes against falling down or dropping after the motor is
switched off, such as through:
– mechanical locking of the vertical axis,
– external brake/catch/clamping device or
– sufficient counterbalance of the axis.
The holding brake of the E MMS-AS -…B is not appropriate for braking the motor. It only
serves for functional holding of t he mo tor shaft. Additional measures are required for use
in safety-oriented applications.
Note
The delay time of the PNOZ relay must be adapted to the application (see Sec-
tion 2.4.5). If this delay time is set too short, the drive carries out an STO function after
this time has expired. This can result in wear of the brake.
Note
The ramp function of the motor controller's Quick Stop delay is not monitored.