Micromod MOD: Modcell 2050R Users Guide - Manual (Page 155)

IB-23C650
BASIC OPERATION
Alarm Messages
An alarm is active when the process input (PROC), input 2 (INP2), control
output (OUT), or deviation value (DEV) exceeds its alarm limit. When an alarm
is active, the alarm indicator flashes and the front panel alarm message for the
appropriate high (HI) or low (LO) turns on and flashes alternately with the
process display. Any such configured alarm output relay is also active. The
alarm remains on until the variable returns to a value within the preset limits;
then it extinguishes. These alarm messages alternate with the alarmed
variables value when the alarm is unacknowledged: [PROC HI], [PROC LO],
[INP2 HI], [INP2 LO], [DEV HI], [DEV LO], [OUT HI], and [OUT LO].
Alarm Trip Points
The high and low alarm trip-points for the controller are determined at the time
of setup; refer to Table 10 Alarms Setting Menu (ALARMS MENU). Process
and deviation are triggered by the process input. A process alarm trips when
the process reaches a preset high or low trip-point. A deviation alarm trips
when the process value deviates from the controller set-point by a preset
amount. An input 2 alarm trips when the input 2 value reaches a preset high
or low trip-point. An output alarm is activated when the control output reaches
a preset high or low trip-point. Alarms resulting from rising values are defined
as high, and those resulting from falling values are defined as low.
Alarm Priority
One of two possible priorities (1 and 2) can be assigned to an alarm. Alarm
priority can be used to display a more important alarm before a less important
alarm. Priority one (1) is the higher priority and any alarm message of this
priority will flash instead of any priority two (2) message.
Beep on Alarm Occurrence
The controller can be configured in the ALARMS MENU to beep on the
occurrence of specific levels of alarms (priority 1, priority 2, or diagnostic).
Whenever the specified level of alarm becomes active, the beeper will sound
alerting the operator to the alarm.
Alarms with Acknowledgment
Alarm acknowledgement can be configured in the ALARMS MENU to be
required for specific levels of alarms (priority 1, priority 2, or diagnostic). If an
alarm for which acknowledgement is required has become active, the alarm
indicator will flash and the alarm type (e.g. PROC HI) will alternately flash with
the process value until the alarm has been acknowledged, even if the alarm
condition has ceased to exist. If the alarm condition still exists after the time
of alarm acknowledgment, just the alarm indicator will remain light (but not
flashing) indicating that the alarm has been acknowledged but is still present.
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