NOVUS Web Server – WS10 - Manual (Page 14)

Web Server – WS10
NOVUS AUTOMATION 14/33
ALARMS SUPERVISION CONFIGURATION
The WS10 can compare the value of any register against limits defined as constants or other registers. The result of the comparison is assigned to
a new alarm register. Based on the result of the alarm, registers can be written to, allowing the WS10 to take actions based on the detected alarm
condition. Some examples of actions that can be executed by the WS10 when an alarm condition is detected:
•
Write to a local output register, allowing local signaling of the alarm condition.
•
Write to registers of external Modbus devices, taking alarm actions on other parts of the system.
•
Enable the WS10 data logger function to start logging critical values of the system under abnormal conditions.
•
Trigger email messages containing process information and informing the start or end of an alarm condition.
The alarm function is enabled when the ALARMS.CFG file is installed on the WS10. Follows an example of the ALARMS.CFG file:
[Alarm1]
Condition=TT101/PV > 200
Hysteresis=2
<SetList>
_INTERNAL_/OUT1=1
TT101/RUN=0
<ResetList>
_INTERNAL_/OUT1=0
[Emerg1]
Condition=TT201/TVALS[3]<=_INTERNAL_/MEM01
Hysteresis=1
<SetList>
_INTERNAL_/OUT2=1
<ResetList>
_INTERNAL_/OUT2=0 Each section defines a new alarm, and the name of the section defines a
tag name on the _ALARMS_ device. This read-only tag contains alarm
status.
Under each alarm section, an alarm condition is defined from the
comparison of a register value and a constant value or from the comparison
of 2 registers values. Many comparison operators can be used.
At the <SetList> sub-section of each alarm a list of write operations can be
defined. These write operations will be executed when the alarm condition
starts.
At the <ResetList> sub-section of each alarm a list of write operations can
de defined. These write operations will be executed when the alarm
condition ends.
Multiple alarm sections can be defined.
Section Sub-section Parameter Values Description
Condition
Device/Tag
Operator
Device/Tag
or
Device/Tag
Operator
Numerical constant
Defines the alarm activation condition. The alarm is activated when
the condition results true. The comparison may be between 2 tag
values or one tag and one constant value. The allowed comparison
operators are: >, <, >=, <=, = e <>.
In a typical application, an local input register is compared against a
memory register. The value of this memory register is programmed by
the operator through an HTML page on the browser screen.
Hysteresis 0 to 30000
Hysteresis for the end of the alarm condition. Example. If the alarm is
activated above 200 and the hysteresis is 2, then the alarm will be
deactivated below 198.
SetList Device/Tag Value for the register
List of register identifications and values. The values will be written to
the registers when the alarm condition begins.
Alarm Name
With up to 6
characters or
digits
ResetList Device/Tag Value for the register
List of register identifications and values. The values will be written to
the registers when the alarm condition ends.
Multiple alarms can be defined, one in each section as the one described above.
When the ALARMS.CFG file is installed, a new device named _ALARMS_ is created on the WS10. This device contains tags with the same names
of the alarm sections on the file. The values of these alarm registers correspond to the status of each alarm, with value zero for an inactive alarm
and one for an active alarm condition. Typically these alarm registers are used to trigger email messages and displayed on the browser screen.
REFERENCE TO THE WS10 ALARM TAGS
To reference the alarm status tags under the _ALARMS_ device, use the syntax of the example below:
_ALARMS_/HiPres
Alarm registers are read only. A value of 0 indicates an inactive alarm, and a value of 1 indicates an active alarm condition.