Setup
Connection Specifications
maxon motor control
EPOS4 Positioning Controller
Document ID: rel5977
3-61
EPOS4 Module/Compact 50/8 Hardware Reference
Edition: February 2016
© 2016 maxon motor. Subject to change without prior notice.
3.4.6.5
Safe Torque Off I/Os
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.
Table 3-54
STO I/Os – Pin assignment
Figure 3-44
STO-IN1 circuit (analogously valid for STO-IN2)
Module
Header Pin
Compact/CB
Connector
Pin
Signal
Description
–
X9 | 8
V
STO
Activation voltage for STO inputs (+5 VDC)
Note:
Do not use this voltage for any other
purpose
B15
–
V
Aux
Auxiliary output voltage (+5 VDC; I
L
≤
150 mA)
B16
X9 | 7
GND
Ground
B17
X9 | 1
STO-IN1+
Safe Torque Off input 1, positive signal
B18
X9 | 2
STO-IN1
−
Safe Torque Off input 1, negative signal
B19
X9 | 3
STO-IN2+
Safe Torque Off input 2, positive signal
B20
X9 | 4
STO-IN2
−
Safe Torque Off input 2, negative signal
B21
X9 | 5
STO-OUT+
Safe Torque Off output, positive signal
B22
X9 | 6
STO-OUT
−
Safe Torque Off output, negative signal
Safe Torque Off inputs 1…2
Circuit type
Optically isolated input
Input voltage
0…+30 VDC
Max. input voltage
±30 VDC
Logic 0
<1.0 VDC
Logic 1
>4.5 VDC
Input current at logic 1
>2 mA @ 5 VDC
typically 3.2 mA @ 24 VDC
Reaction time
<25 ms