4-15
Safe Torque Off
AC890PX AC Drive
Normal Operation
In normal operation, there can be a small time difference between changes of state on X11/01 and X11/03,
due to different delays in the operation of two sets of relay contacts.
States:
1
Both inputs are low. STO prevents the drive from starting. User output is ON. This is the “safe torque
off” state of the drive.
2
Both inputs are high. Drive is able to run under software control. User output is OFF.
3
One input is high and the other input is low. Drive cannot start due to STO action. User output is
OFF. Normal operation allows this state to persist for up to 1.6 seconds (nominal) which is the
minimum fault detection time required to generate a fault (3.0 seconds is the maximum). These
tolerable time differences are normally caused by switches or relays; they should be kept as short as
possible.
Channel A: X11/01
Channel B: X11/03
Output: X11/05, X11/06
STATE
24V
0V
24V
0V
ON
OFF
1
2
1
3
< 1.6s
3
< 1.6s
Summary of Contents for AC890PX Series
Page 17: ...2 5 Product Overview AC890PX AC Drive 890PX bottom wire entry ...
Page 144: ...The Keypad 7 9 AC890PX AC Drive The Menu System Map ...
Page 145: ...7 10 The Keypad AC890PX AC Drive The Menu System Map continued ...
Page 328: ...Programming D 88 AC890PX AC Drive Functional Description ...
Page 386: ...Programming D 146 AC890PX AC Drive Setpoint Drive Frequency Frequency 1 Frequency 2 ...