STO
–
Safe Torque OFF
Functional description
Operating Manual Rev. 1.3
www.engelantriebe.de
page 9
Figure 6-1: STO function with emergency stop device
Figure 6-2: STO function with OSSD signals
The integrated drive can be supplied by either a PELV or SELV power source.
The safety circuit, i.e. the STO channels, can as well be supplied by either a PELV or SELV power source.
For drives with a supply voltage of 24
V, it is permissible to supply the STO channels from the 24
V power supply of the
integrated drive.
Each STO input and the status output are galvanically isolated from each other and from the control electronics of the
integrated drive.
Note!
An incorrect wiring of the STO inputs can result in a lower safety level. By connecting input
„a‟
to „c‟, for example,
the external dual-channel structure of the system is lost.
STO Input 1
STO Input 2
STO Status
Controller
Pulse
Inhibit
Power
Stage
and
Motor
a
b
c
d
S
Emergency Stop
Device
GND
24 VDC
SELV/PELV Power Supply
HFI-Sx00
STO Input 1
STO Input 2
STO Status
Controller
Pulse
Inhibit
Power
Stage
and
Motor
a
b
c
d
S
OSSD
Switching Device
GND
24 VDC
SELV/PELV Power Supply
Output 1
Output 2
HFI-Sx00
Test Pulses
