BE1-951
Reporting and Alarm Functions
6-33
D2850-09.vsd
06-29-99
R A - M A J = 0
Logic
A l a r m
R e s e t
Logic
R A - M I N = 0
A R S T K E Y
H M I R E S E T K E Y
Figure 6-5. Programmable Alarm Function
Retrieving and Resetting Alarm Reports
When an alarm condition occurs, the appropriate
front panel LED lights and HMI screen 1.3 is
displayed. (See Section 10, Human-Machine
Interface for more information about automatic
display priority logic.) The HMI display scrolls
between displaying all active alarm points. This
includes alarms that are not programmable (relay
trouble alarms). Any latched alarms that aren’t
currently active can be reset by pressing the HMI
Reset key.
Logic variables for ALMMAJ, ALMMIN, and ALMLGC can also be set to operate any of the output contacts
to give an indication that an alarm condition exists. Section 7, BESTlogic Programmable Logic provides
more details about this feature.
The status of the three front-panel LEDs (Relay Trouble, Minor Alarm, and Major Alarm) can be read through
the communication ports by using the RG-STAT command. Alarm status is given in the DIAG/ALARM line
of the General Status Report. Refer to the General Status Reporting subsection for more information about
obtaining relay status with the RG-STAT command. Figure 6-4 shows the alarm reset logic.
The Reset key of the HMI is context sensitive. That is, the functionality depends upon what screen is
currently being displayed. BESTlogic variable ARSTKEY takes advantage of this to allow the front panel
Reset key to be used in the programmable logic scheme when alarm screen 1.3 is active. An example of
the use of this logic variable is to break the seal-in for a logic expression. The logic expression can be
programmed so that the seal-in function uses VO13, VO14, or VO15. If the virtual output expression is
included in one of the programmable alarm masks, the automatic display priority logic will cause the display
to go to alarm screen 1.3. When the HMI Reset key is pressed, the ARSTKEY logic variable is asserted and
the logic expression seal-in is broken. See Section 8, Application, Application Tips for more information.
Pressing the HMI Reset key while the alarm screen is displayed, will clear any latched alarms that are not
currently active. Refer to Table 6-16 for a list of latching alarm points and self clearing alarm points. Figure
6-4 shows the alarm reset logic.
The RA (report alarms) command can be used to read detailed alarm reports and reset latched alarms.
RA Command
Purpose:
Read or reset alarm information.
Syntax:
RA[-<type>][=0]
Comments: type = LGC (Logic), MAJ (Major), MIN (Minor), or REL (Relay)
Privilege G or R password access is required to reset alarms.
RA Command Examples
1.
Read the current alarm status.
>RA
RA-LGC NONE
RA-MAJ NONE
RA-MIN ALARM# 16 - SETTING CHANGE
RA-FAIL NONE
2.
Clear the latched minor alarm
>RA-MIN=0
Links Between Programmable Alarms and BESTLOGIC
Several links between the programmable alarms and BESTlogic allow alarm functions to be used in the logic
scheme and programmable logic functions to be used in the alarm reporting function.
