How To Produce An Alarm Signal - Omega FDT-25W User Manual

FDT-25W Wall Mounter Ultrasonic Flowmeter
The totalizer output will produce a pulse output with every unit flow of the totalizer.
The totalizer pulse output can only be realized by mapping the pulse output to the OCT or BUZZER
hardware devices.
For example, assume that the POS totalizer pulse output is needed, and every pulse should represent
0.1cubic meter of liquid flow; the pulse output will be mapped to the internal Buzzer, so that with every
0.1 cubic meter of flow the BUZZER will beep for a while.
The following setups should be taken / performed:
(1) Select the unit Cubic Meter under window M32.
(2) Select the Multiplier as '2. X0.1' under window M33.
(3) Select the output option '9. POS INT Pulse' under window M77. (INT stands for totalized )

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:
(1) There is no receiving signal
(2) There is poor signal received.
(3) The flow meter is not in normal measurement modes.
(4) Reverse flow.
(5) Overflow occurs at the analogue output by 100% or more
(6) 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 /h and
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greater than 1000m /h. The following setup steps would be recommended:
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(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
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