Fail-Safe Mode Power Supply - Festo CAMC-G-S3 Manual

5 Operation
5.3.3

Fail-safe mode power supply

The core of the activation of the outputs is the so-called "fail-safe mode power supply". Each microcon­
troller uses a dynamic signal to generate its own (internal) auxiliary power supply (U_FS1, U_FS2) to
activate the different (safe) outputs for
– the power supply for driver activation, separately for the top and bottom switches,
– brake activation, separate for the BR+ and BR- circuit breakers,
– the digital outputs DOUT40 – DOUT42, separate for Pin A and Pin B.
U_FS1 affects the outputs activated by microcontroller 2, and, in return, U_FS2 affects the outputs of
microcontroller 1. This ensures that, if there is an error, each microcontroller can switch off the outputs
of the other microcontroller.
When a microcontroller fails (for whatever reason - hardware error, program crash, etc.), the corres­
ponding "Fail-safe mode" power supply fails and the outputs are switched off.
5.3.4 Protective functions for the digital outputs
The digital outputs are protected against:
– Short circuit to 0 V and 24 V and PE
– Any cross circuits to other outputs
– Voltage surge to 60 V
During operation, active outputs are monitored using test pulses.
If there is an error, the outputs are switched off, possibly all at the same time.
5.3.5 Protective functions for the digital inputs
The digital inputs are protected against:
– Short circuit to 0 V and 24 V and PE
– Any cross circuits to other outputs
– Surge malfunctions
– Voltage surge to 60 V
During operation, the inputs are monitored using internal test pulses.
The connected passive sensors are monitored using external test pulses via DOUT4x.
In the case of multi-channel inputs, a plausibility check takes place for simultaneous switching with
discrepancy time monitoring.
5.3.6 Protective functions for the brake activation
The outputs for brake activation are protected against:
– Short circuit to 0 V and 24 V and PE
– Any cross circuits to other outputs
– Voltage surge to 60 V
During operation, the active outputs are monitored using test pulses.
If there is an error, the outputs are switched off.
Festo – GDCP-CAMC-G-S3-EN – 1406NH – English 201