Alstom iSTAT M355, Руководство пользователя

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M3x5/EN M/B User Manual
Page 64
iSTAT M3x5
10.13.2.2 Compare time delay
This setting defines the delay time (if required) between satisfying the alarm condition and
alarm activation. If the alarm condition exists or a shorter time than the delay defined, the
alarm will not be triggered.
This setting is used to remove sporadic and very short duration events.
10.13.2.3 Hysteresis
This setting defines the alarm deactivation hysteresis.
When a monitored quantity is close to the defined alarm value small variations can generate
numerous alarms. Hysteresis should be set according to the expected variation of the
monitored quantity.
10.13.2.4 Response time
This setting defines the alarm response on measured quantity.

Normal response: In this case the monitored quantity is averaged according to display
averaging settings (0.1 to 5s).

Fast response: In this case the alarms react on non-averaged measurements (1 signal
period).
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This setting should be used according to the required functionality. Fast
response is more prone to glitches and transient effects in a system but
reaction time is fast.
10.13.3 Individual Alarm settings
FIGURE 10-13: ALARM SETTINGS
For each individual alarm a parameter, value (actual value or MD thermal) and the condition
for alarm switching are defined. In addition it is defined if a relay is to be switched and a
beep on alarm.
Note : If the ‘Used’ ranges are changed after the alarm settings have been defined, then the
alarm settings will be modified automatically, see section 10.5.3. It may be necessary to
subsequently modify the settings for the alarm outputs.
If a digital input module is fitted to the unit, then the status of the input can be defined as the
parameter.
10.13.3.1 Parameter
This setting defines a quantity that should be monitored. It is also possible to select process
quantities from I/O modules.