Safe Torque Off I/Os - maxon motor EPOS4 Module 50/5 Hardware Reference Manual

3.4.8
The STO (Safe Torque Off) function can be utilized to bring the drive to a torque-free, safe condition via
two independent inputs. The drive output power stage is switched off if either one of the inputs is not
powered.
For in-depth details on the STO functionality separate document «EPOS4 Application Notes».
Activation of power stage
In order to activate the power stage, both STO inputs must be powered.
Module
Header Pin
Table 3-53
Circuit type
Input voltage
Max. input voltage
Logic 0
Logic 1
Input current at logic 1
Reaction time
Figure 3-42
maxon motor control
EPOS4 Positioning Controller
EPOS4 Module/Compact 50/5 Hardware Reference

Safe Torque Off I/Os

Compact/CB
Connector
Pin
– X9 | 8
B15 –
B16 X9 | 7
B17 X9 | 1
B18 X9 | 2
B19 X9 | 3
B20 X9 | 4
B21 X9 | 5
B22 X9 | 6
STO I/Os – Pin assignment
STO-IN1 circuit (analogously valid for STO-IN2)
Document ID: rel8003
© 2018 maxon motor. Subject to change without prior notice.
Signal
Activation voltage for STO inputs (+5 VDC)
V
Note: Do not use this voltage for any other
STO
purpose
V Auxiliary output voltage (+5 VDC; I
Aux
GND Ground
STO-IN1+ Safe Torque Off input 1, positive signal
STO-IN1− Safe Torque Off input 1, negative signal
STO-IN2+ Safe Torque Off input 2, positive signal
STO-IN2− Safe Torque Off input 2, negative signal
STO-OUT+ Safe Torque Off output, positive signal
STO-OUT− Safe Torque Off output, negative signal
Safe Torque Off inputs 1...2
Optically isolated input
0...+30 VDC
±30 VDC
<1.0 VDC
>4.5 VDC
>2 mA @ 5 VDC
typically 3.2 mA @ 24 VDC
<25 ms
Edition: May 2018
Setup
Connection Specifications
Description
≤150 mA)
L
3-59