STACIS
2100 Piezoelectric Isolation System - Installation & Operation Manual
P/N 96-28765-01
Page 29 of 43
5.3.8
LF/HF Alarms
This is the menu option for enabling or disabling the alarms for Oscillation Control and Saturation Control.
These two features monitor the operation of the STACIS
system for oscillation and saturation,
respectively (see Oscillation Control and Saturation Control sections above). Whenever oscillation or
saturation is detected, the controller automatically attempts to correct the problem. If the automatic
adjustment fails, an “Alarm” (if enabled) condition is indicated by:
-
a message on the LCD showing the axis and type of alarm.
Note:
To acknowledge the message and
to clear it from the LCD, press the
Previous
key;
-
the System Status LED turns from green to flashing amber;
-
Alarm Relay by triggers (see Table 3).
In addition, the affected axis is disabled to prevent damage to the actuator.
Two types of alarm condition may occur: an “LF” (Low-Frequency) Alarm or an “HF” (High-Frequency)
Alarm.
Low-Frequency Alarms happen when the control signal to an actuator exceeds a specified value for an
extended period of time. If Saturation Control is enabled
(strongly recommended default)
, the system
gains are automatically adjusted to prevent saturation of the actuator from ever developing. Therefore, if
Saturation Control is enabled, LF Alarms will never be triggered. If Saturation Control reduces the gain
by large amounts, a warning can be sent over the controller’s COM port interface (if enabled).
High-frequency Alarms happen when the system detects an oscillation. The system monitors the period
and amplitude of the signals to the HVAs. If the system oscillates - signal with a regular period and high
amplitude detected - for longer than a specified time period, then an Alarm is triggered, and the channel is
disabled.
It is strongly recommended that the Alarms stay enabled.
Disabling them could
cause permanent damage to the actuators from uncontrolled oscillation. The option to
turn the alarms off is mainly a diagnostic tool.
