Eurotherm 6100, Руководство пользователя

Страница: 86 / 397

100/180MM DISTRIBUTED GRAPHIC RECORDER: USER GUIDE
Page 70 HA029324
Issue 11 Oct 14
4.3.3 CHANNEL/ALARM CONFIGURATION (Cont.)
ENABLE
Allows the alarm to be defi ned as Off, Unlatched, Latched or Trigger.
Off Alarm is disabled and the remainder of the alarm confi guration 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 (fl ashing before acknowledgment - steady after acknowledgement)
until the alarm clears.
Alarm messages are printed if enabled in group confi guration.
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 (fl ashing 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 confi guration.
Continuous jobs remain active only whilst the alarm trigger source is active. I.E. the
job fi nishes 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 fi eld appears only when the alarm Enable is not selected Off. Each alarm can be defi ned as absolute
high, absolute low, deviation-in, deviation-out, rate-of-change rise or rate-of-change fall.
Absolute High As shown in fi gure 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 hysteresis). If a dwell value is defi ned, the alarm does not
become effective until this dwell time has been exceeded.
Absolute Low As shown in fi gure 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 defi ned, the alarm does not be-
come effective until this dwell time has been exceeded.
Deviation in As shown in fi gure 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 Hysteresis). If a dwell value is defi ned, the
alarm does not become effective until this dwell time has been exceeded.
Deviation out As shown in fi gure 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 en-
ters the band: Reference ± (Deviation - Hysteresis).If a dwell value is defi ned, the alarm
does not become effective until this dwell time has been exceeded.
Rate of change As shown in fi gure 4.3.3f, rate of change alarms become active whenever the signal
value changes by more than a specifi ed amount within a specifi ed period. If a dwell
value is defi ned, 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 .
SETPOINT SOURCE
Allows the user to choose either a fi xed, user-defi ned value (constant) or the value of another point (input
channel, maths channel, totaliser etc.) to be chosen as the trigger point. In the latter it is possible, for
example, to trigger an alarm, when one channel’s value rises above, falls below etc. the value of a second
channel.