Everest CORE - Product Manual |
Application Guide
INGENIA | 08/01/2019
34
Schematic
Signals description
Signal
Description
+3.3V_D
+3.3V Logic supply
\STO_IN_1 Safe Torque Off inputs positive terminal
\STO_IN_2
STO_RET
Safe Torque Off inputs negative or reference terminal
\STO1
To be connected to pin 33 of Everest CORE Interface connector
\STO2
To be connected to pin 34 of Everest CORE Interface connector
GND_D
Logic supply reference voltage. To be connected to pin 32 of Everest CORE Interface connector
Design Notes
•
STO_RET is tied together from the 2 circuits, but could be wired separately.
•
Zener diodes D1 and D2 provide 2 protective functionalities at the same time. First, they protect against
overvoltage of the optocopupler's emitter by saturating voltage thanks to the current limited by resistors R1
and R3. This also expands the operating range of the input to 24 V levels (30 V maximum). Second, they
protect against inverted polarity of the input voltage, as in this case they will conduct current in the forward
direction, and still the current will be limited by resistors R1 and R3.
Care for certification
Note that this circuit may not be compliant with major safety on machinery standards (like IEC 61800 or
others). To get support on targeting this king of certification, please
