Model 2314/2316 SNMP Alarm Encoder
46 2314/2316-042315
Fial Incorporated
Severity: Select the Severity level for the selected Boolean point. The possible Severity levels are:
CR, MJ, MN, and ST.
Service Affecting: Select Yes if the selected Boolean point is Service Affecting, or No if the
selected alarm point is Not Service Affecting.
Expression: Use the list box and buttons along the bottom to build a Boolean expression.
Entering an expression creates a new alarm point whose state depends on specified
combinations of other alarms. You create expressions using the true/false state of any alarm
point, status point, control point or analog point, combined in various ways with the true/false
state of one or more additional alarm, status, control or analog points. A built-in Boolean
expression checker helps enforce the correct syntax.
Note: An analog point is ‘true’ (asserted) only if the current value exceeds the high or low
threshold setting for that point.
Alarm and control point names can be quite long. The maximum length of an expression is
128 characters. A pop-up box will warn you when reaching that limit. Therefore, abbreviations
are automatically used within the Boolean expression when the expression is created. The
appropriate point number is appended to the abbreviation. Alarms are signified by the
abbreviation “AL” (AL1 to AL8), Controls are signified by the abbreviation “C” (C1 to 4) and
Analog alarms by the abbreviation “AN” (AN1 to AN4).
The simplest example of a Boolean Alarm is one that depends on the combined state of two
points. If you want a Boolean Alarm to be asserted when both hardware points are asserted,
just AND them together. For example, suppose there are two predefined alarm points, named
“Tower Beacon” (AL3) and “Tower Side Light” (AL4). You want to create a new Boolean
Alarm point (#1) that is asserted when both AL3 and AL4 are asserted.
Start by selecting the desired point number from the Edit Boolean Point drop-down list (select
#1 for this example). This will typically be an unused point number. Enter a descriptive name
for the new point, something like “All Tower Lights Out.” Note: Only alphanumeric and space
characters are allowed. Enter the correct Severity level and Service Affecting state for the new
Boolean Alarm point in the corresponding boxes. In this example change the Severity to “CR”
and leave the Service Affecting state at “No.”
Next, build the expression. Select the first point for the expression from the scrollable point list
box (see Figure 33). You may need to use the thumb-bar to get to the desired point. In this
example select “AL3 Tower Beacon.” Notice that the point abbreviation is listed for alarm
point #3 before the point name. With the correct point selected, click on the AddPoint button
at the bottom of the dialog screen. Notice that the point abbreviation (AL3) has been added to
the expression field (gray area at the bottom of the dialog) as shown in Figure 33. Only
function and operator buttons that are appropriate for the next entry in the expression are
enabled after each entry is made (light gray and able to be highlighted). Notice that you can
now only select from the AND, OR, XOR,) and UNDO buttons for the next entry.
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