Parker AC890PX Series, Product Manual

Page: 79 / 517

4-13
Safe Torque Off
AC890PX AC Drive
Truth Table
Overview
STO
Input A
X11/01
STO
Input B
X11/03
Drive Function
STO
Status
Output
X11/05,
X11/06
STO Active
0V 0V
Drive cannot start or supply power to its motor. STO trip
reported if drive is running or drive start is attempted.
This is the intended safe state of the product with
correct dual-channel operation.
ON
Abnormal one-
channel
operation
detection
24V 0V
Drive cannot start or supply power to its motor. STO trip
reported if drive is running or drive start is attempted. If
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).
This is single channel operation and thus deemed not
as intended for category 3 / PLe/ SIL3 structure
implementation.
OFF
0V 24V
STO Inactive 24V 24V
Drive is enabled to run under software control. The drive
can supply power to its motor.
OFF