Bronkhorst Multibus - Manual (Page 29)

BRONKHORST ®
Page 29 Operational instructions for digital multibus instruments 9.17.023
6.13 U
SING 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:
Action Parameter Value
Maximum alarm on 90%. send to Alarm maximum limit 28800
Minimum alarm on 10%. send to Alarm minimum limit 3200
No new setpoint wanted at crossing alarm limit. send to Alarm setpoint mode 0
Reset alarm enable * 12
Delay on action at output should be 10 seconds. send to Alarm delay time 10
Reset should be automatically, when signal
comes into safe area again or via FLOW-BUS.
send to Alarm mode 1
*) 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:
Action Parameter Value
Maximum alarm limit on setpoint + 3%. send to Alarm maximum limit 960
Minimum alarm limit on setpoint – 0.9%. send to Alarm minimum limit 288
Setpoint wanted at crossing alarm limit = 0%.
send to Alarm setpoint mode 1
send to Alarm new setpoint 0
send to Reset alarm enable * 5
Delay on action at output should be 2 minutes. send to Alarm delay time 120
Reset via keyboard or BUS/RS232. send to Alarm mode 2
*) 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.