Truth Table - Parker AC890PX Product Manual

4-13
Safe Torque Off

Truth Table

Overview
STO Active
Abnormal one-
channel
operation
detection
STO Inactive
STO STO
Input A Input B
X11/01 X11/03
Drive cannot start or supply power to its motor. STO trip
reported if drive is running or drive start is attempted.
0V 0V
This is the intended safe state of the product with
correct dual-channel operation.
Drive cannot start or supply power to its motor. STO trip
reported if drive is running or drive start is attempted. If
24V 0V
either of these conditions persists for more than 3.0
seconds (the maximum fault detection time), the STO
function will lock into a fault state. The drive cannot start
until the fault is rectified, all power is removed and
reapplied (both mains and any auxiliary 24V dc power).
0V 24V
This is single channel operation and thus deemed not
as intended for category 3 / PLe/ SIL3 structure
implementation.
Drive is enabled to run under software control. The drive
24V 24V
can supply power to its motor.
Drive Function
STO
Status
Output
X11/05,
X11/06
ON
OFF
OFF
AC890PX AC Drive