28 Instruction Manual
4.17 How to produce an alarm signal
There are 2 types of hardware alarm signals that are available with this instrument. One is
the Buzzer, and the other is the OCT output.
Both for the Buzzer and OCT output the triggering sources of the event include the
following:
There is no receiving signal
There is poor signal received.
The flow meter is not in normal measurement modes.
Reverse flow.
Overflow occurs at the analogue output by 100% or more
Overflow occurs at the frequency output by 120% or more.
(7) The flow rate is out of the specified range which is configured in windows M73 and M74
for Alarm #1, and in windows M75 and M76 for Alarm #2.
Example A: assume we need the Buzzer to start beeping when the flow meter is not ready
in normal measurement. Switch to M77, select item "2. Abnormal Measurement State"
Example B: assume we need the Buzzer to start beeping when the flow rate is less than
300 m
3
/h and greater than 1000m
3
/h. The following setup steps would be recommended:
(1) Enter flow rate lower limit 300 in M73 for #1 alarm,
(2) Enter flow rate upper limit 1000 in M74 for #1 alarm,
(3) Select item '6. Alarm #1' in M77.
Example C: assume we need the OCT output to activate when flow rate exceeds
100~500m
3
/h and the relay output to activate when flow rate exceeds 600~1000m3/h.
The following setup steps would be recommended:
(1) Enter flow rate lower limit 100 in M73
(2) Enter flow rate upper limit 500 in M74
(3) Enter flow rate lower limit 600 in M75
(4) Enter flow rate lower limit 1000 in M76
