Operator Terminal System Manual - 11276916.pdf

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Unit Functions
8 Alarm handling
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Parameter Description
To printer This parameter defines whether the alarm message will be output directly to the
printer when the alarm status changes.
Repeat count If the checkbox is activated, a counter for the alarm in the alarm list will be displayed.
The counter is incremented each time an alarm is triggered. The alarm
must be acknowledged to enable the alarm to appear in the list as new alarm
message.
Import See section "Alarm import" on page 183.
The value defined for an analog alarm signal cannot be controlled via register.
Hysteresis is not supported. Only 16-bit values are supported.
Alarm settings General settings for alarms and the alarm list are made under the menu item [Setup] /
[Alarm settings]. The space required by alarms in the alarm lists depends on the length
of the alarm text and the number of objects. The space required by an alarm can be
calculated using the following formula.
S= 42 + NC
S = Number of bytes
NC = Number of characters in the alarm text
The alarm list will be rewritten when it is full. 25% are deleted from the list when it is
rewritten. This means 75% of the previous content will be retained.
Example:
The length of the alarm text is 38 characters. This means each alarm requires 80 bytes
in the alarm list. The result is 1024 (list size=1 kB)/80 => maximal 12 alarms in the alarm
list. When the 13th alarm is issued, the alarm list will be rewritten and only includes the
last nine alarms.
Parameter Description
Active signal Indicates the digital signal that will be issued by the terminal if the alarm is active.
Unack. signal Indicates the digital signal that will be issued by the terminal when the alarm is not
acknowledged.
List erase signal Indicates the activated digital signal that deletes deactivated alarms from the alarm
list.
Reset Means that the list erase signal is deactivated when the alarm list is cleared.
List size (kilobytes) Provides the list size in kB for DOP11A-20 to DOP11A-50
Note: If the system assigns the same amount of memory as is indicated for the list
size, the list size will double. If the list size exceeds 10 kB, the performance of the
project will be influenced negatively.
Enable alarm signal Digital signal that, if enabled invokes alarm handling in the terminal. This parameter
allows to activate or deactivate alarm handling in the terminal. Do not use this
parameter if you want alarm handling to be active permanently.
Default font size Specifies the preset font size for the alarm list. The standard font size in the alarm
list is always displayed after a start or restart and when switching between operating
modes.
186 System Manual – DOP11A Operator Terminals