![background image](http://html1.mh-extra.com/html/omega/fdt-25/fdt-25_user-manual_4104833023.webp)
FDT-25 Handheld Ultrasonic Flowmeter
19
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 )
§3.17 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) Alarms on when there is no receiving signal
(2) Alarms on when there is poor signal received.
(3) Alarms on when the flow meter is not in normal measurement modes.
(4) Alarms on reverse flow.
(5) Alarms on the overflow of the Frequency Output
(6) Alarms on when the flow is out of a designated range set by the user.
There are two out-of-normal-range alarms in this instrument. They are called #1 Alarm and #2 Alarm.
The flow range can be user-configurable through M73, M74, M75, M76.
For example, assume that the Buzzer should start beeping when the flow rate is less than 300 m3/h
and greater than 2000m3/h, the following steps for setups would be recommended.
(1) Enter 300 under M73 for #1 alarm low flow rate
(2) Enter 2000 under M74 for #1 alarm high flow rate
(3) Select the item reading like ‘6. Alarm #1’ under M77.
§3.18 How to use the built-in Buzzer
The built-in buzzer is user-configurable. It can be used as an alarm. Use M77 for setups.
§3.19 How to use the OCT output
The OCT output is user-configurable, which can be performed by selecting the proper input source
such as pulse output.
Use M78 for the setups.
Please make sure that the Frequency Output shares the OCT.
The OCT output shares pins with the RS-232C interface, and the terminal is at Pin 6 and the ground
is at Pin 6.
§3.20 How to modify the built-in calendar
No modification on the built-in calendar will be needed in most cases. The calendar runs on insignificant
amount of power supply. Modification will be required only in such cases as when the battery is
totally consumed, or when the changing of the battery takes a long time.