Future Design MCT-CM, Руководство пользователя

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MCT-CM
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Latch: When latching is enabled, the alarm will remain active even after the alarm condition has passed
until acknowledged by the user. Latched alarms are acknowledged by the user when pressing
the ‘Reset’ button on the Alarm screen or by activating a digital input configured for ‘Remote
Alarm Reset’. An alarm that does not having latching enabled (self-clearing) will deactivate
automatically when the alarm condition has passed.
NOTE: Latching alarms are acknowledged even when the alarm condition is still present when
the user activates the alarm reset. The latched alarm will then automatically clear once
the alarm condition is no longer present. If the alarm reset was not activated during the
alarm period, the alarm will remain latched until the user activates the alarm reset.
Reverse: When turned on, the digital output assigned to the alarm will be energized in a non-alarm
condition, i.e., fail-safe. When turned off, the digital output assigned to the alarm is normally
open and will close in an alarm condition.
Silent: This is used to control the method by which an alarm is reported. When turned off, an alarm
condition will trigger the audible alarm and the alarm notification icon will flash to indicate the
alarm condition. The buzzer must then be manually silenced by pressing the reset button on the
alarm screen.
If silent mode is on, the audible alarm will not sound when the alarm condition occurs. If the
alarm latch is turned off, the alarm will not be reported on the alarm screen. If the alarm latch is
turned on, which requires manual reset by the operator, the alarm will be reported on the alarm
screen in order to notify the user to reset the alarm; however, the alarm notification icon will not
flash. The user must navigate to the alarm screen in order to determine if a latched alarm is
present.
Start Delay:
When the start delay is off, the alarm will activate immediately when the input exceeds the alarm
set points as programmed. When the start delay is on, the input must first enter the normal
operating range (be above the low alarm set point and/or below the high alarm set point) before
the alarm can be activated. Upon the next excursion beyond the alarm set points, the alarm will
then activate.
The start delay feature is typically used on processes that, when in the off state, are in an alarm
condition. This allows the process to be started prior to the alarm(s) being activated and shutting
down the process.
NOTE: The alarm start delay, when activated, inhibits alarm action from power-up of the MCT,
or when entering
‘online’ mode.
The
Digital Output assignment can be used to assign one of the MCT digital outputs to the alarm. When the
alarm activates, the output will work in conjunction with the alarm and turn on when the alarm is active and off
when the alarm is cleared.
NOTE: The selected digital output must be configured as a process alarm output. If the digital output selected
is not configured to be a process alarm output, it will not function according to the alarm settings. See
section 10.8 Digital Outputs for information on how to configure the digital outputs.
9.3.1 Set Points and Alarm Message
The alarm set points and alarm message are accessed by pressing the ‘Setpoints’ button at the lower left of
the Alarm screen.