
BRONKHORST®
Page 29 Operational instructions for digital multibus instruments 9.17.023
6.13 USING AN ALARM (EXAMPLES)
Using the alarms will take three steps:
1. Preparing the instrument (setting correct values for mode, limits etc.)
2. Monitoring the alarm info byte (gives info which alarm has occurred)
3. Resetting the alarm (will re-initialize the alarm and set output to normal values again)
6.13.1 Using maximum and minimum alarm
This alarm will check if the measured signal crosses the maximum or minimum limit set by the user.
Example
Send following parameter values:
No new setpoint wanted at crossing alarm limit.
Delay on action at output should be 10 seconds.
Reset should be automatically, when signal
comes into safe area again or via FLOW-BUS.
*) Default all reset inputs are enabled, so this command isn’t really necessary
Now the alarm will be active.
Alarm status can be monitored by means of parameter alarm info.
Resetting the alarm will need the following command reset = 0 and then reset = 2.
To inactivate the alarm, put it in alarm mode “off”. This will also reset your outputs.
This can be done sending command: alarm mode = 0.
6.13.2 Using instrument with response alarm
This alarm will check if the measured value will come within an area limited by maximum limit and minimum limit,
related to the setpoint, within a certain delay-time.
Example
Send following parameter values:
Maximum alarm limit on setpoint + 3%.
Minimum alarm limit on setpoint – 0.9%.
Setpoint wanted at crossing alarm limit = 0%.
Delay on action at output should be 2 minutes.
Reset via keyboard or BUS/RS232.
*) Default all reset inputs are enabled, so this command isn’t really necessary
Now the alarm will be active.
Alarm status can be monitored by means of parameter alarm info.
Resetting the alarm will need the following command reset = 0 and then reset = 2.
To inactivate the alarm, put it in alarm mode “off”. This will also reset your outputs.
This can be done sending command: alarm mode = 0.
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