ABB Ability 800xA Series, Операция

Страница: 60 / 332

Alarm Priority Section 3 CCF Displays
60 3BUR002418-600 A
Alarm conditions may also be indicated audibly by a .WAV file. Various
combinations of audible and visual alarm indication can be obtained by
configuration. Refer to the
System 800xA Operations (3BSE036904*) for a
description of the event bar and event display included with the base product.
Alarm Priority
If you are using both the deviation and setpoint limit alarms, it is possible, when
the alarms are not acknowledged and priorities are the same, to see the deviation
active on the faceplate and the setpoint limit active on the loop detail. Use
different priorities.
A priority (High, Medium, Standard) can be assigned to each alarm, Figure 16 .
Alarm priorities are used to display a more important alarm before a less important
alarm when viewing the alarm displays.
Alarm Limits and Limiting
The high and low alarm limit trip-points for each control loop are determined at the
time of configuration and can be modified during operation,
Figure 16 .
Process and deviation alarms are triggered by the process input. A process alarm
trips (becomes active) when the process reaches a preset high or low trip-point. A
deviation alarm trips when the process value deviates from the control loop setpoint
by a preset amount (deviation high value is when the measured value into the PID
FCM is larger than the setpoint and deviation low value is when it is less than the
setpoint).
An output alarm is activated when the control loop output reaches a preset high or
low limit. Alarms resulting from rising values are defined as high, and those
resulting from falling values are defined as low. The terms high high and low low
Figure 16. Alarm Limit and Priority Settings