100 MM GRAPHICS RECORDER: USER GUIDE
HA027271
Issue 12 Mar 04
User Guide
Page 54
4.3.3 CHANNEL/ALARM CONFIGURATION (Cont.)
ALARM NUMBER
Allows an alarm to be selected for configuration. (One or two for 16MB DRAM recorders; one to four for 32MB
versions.)
ENABLE
Allows the alarm to be defined as Off, Unlatched, Latched or Trigger
Off
Alarm is disabled and the remainder of the alarm configuration is hidden.
Unlatched
Unlatched alarms become active when the trigger source becomes active and remain active
until the source returns to a non-active state.
The indicator is on (flashing before acknowledgment - steady after acknowledgement) until
the alarm clears.
Alarm messages are printed if enabled in group configuration.
Latched
Latched alarms become active when the trigger source becomes active and remain active until
the alarm is acknowledged AND the trigger source has returned to a non-active state.
The indicator is on (flashing before acknowledgment - steady after acknowledgement) until
the alarm has been acknowledged AND the trigger source has returned to a non-active state.
Alarm messages are printed if enabled in group configuration.
Continuous jobs remain active only whilst the alarm trigger source is active. I.E. the job
finishes when the alarm clears, whether acknowledged or not.
Trigger
When triggered all associated jobs are initiated, and continuous jobs remain active until the
alarm clears. There is no alarm indication, and no messages are printed.
TYPE
This field appears only when the alarm Enable is not selected Off. Each alarm can be defined as absolute high, abso-
lute low, deviation-in, deviation-out, rate-of-change rise or rate-of-change fall.
Absolute High
As shown in figure 4.3.3d, an absolute high alarm becomes active when the channel value exceeds the
threshold value. The alarm remains active until the channel value falls below (Threshold minus hyster-
esis). If a dwell value is defined, the alarm does not become effective until this dwell time has been ex-
ceeded.
Absolute Low
As shown in figure 4.3.3d, an absolute low alarm becomes active when the channel value falls below the
threshold value. The alarm remains active until the channel value exceeds (Thr hysteresis). If a
dwell value is defined, the alarm does not become effective until this dwell time has been exceeded.
Deviation in
As shown in figure 4.3.3e, a deviation-in alarm becomes active whenever the channel value enters the
band: Reference
±
Deviation. It remains active until the channel value leaves the band: Reference
±
(De-
v Hysteresis). If a dwell value is defined, the alarm does not become effective until this dwell
time has been exceeded.
Deviation out
As shown in figure 4.3.3e, a deviation-out alarm is active whenever the channel value leaves the band
Reference
±
Deviation. It remains active until the channel value enters the band: Reference
±
(Devia-
tion - Hysteresis). If a dwell value is defined, the alarm does not become effective until this dwell time
has been exceeded.
Rate of change
As shown in figure 4.3.3f, rate of change alarms become active whenever the signal value changes by
more than a specified amount within a specified period. If a dwell value is defined, the alarm does not
become effective until this dwell time has been exceeded. An averaging period can be set to remove the
effects of sudden, but short-lived changes, such as noise spikes on the signal.
Note: Alarm icons appear at the display, as described in section 3 of this manual.
