Product Manual

Wall Mounted Ultrasonic Flowmeter---User Manual
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Before making the wiring, please refer to the figure in Appendix8.1.
4.1 External SD Data Logger
The external SD data logger is installed inside enclosure of wall mounted unit, and steal 3.3VDC
power from the flowmeter, and doesn’t external power supply. For more details, please contact us
if you have such request.
4.2 4-20mA Analog current output connection/setup
The 4-20mA output of the flowmeter is self-powered way which doesn’t require external power to
the wire of current loop. Its accuracy is better than 0.1%. It can be configured into different mode,
such as 4-20mA mode, 0-20mA mode, etc. Mode selection can be made in menu M55.
In order to make 4-20mA work well, it need to make wire connecting on hardware and setting on
software. Please refer to the figure in Appendix 8.1 for wiring terminals.
Firstly, well connect wire to AO+ (Pin23) and AO-(Pin22). Then, make the setting on software of
the flowmeter as below:
1) Select the mode to be 4-20mA in menu M55
2) Set flow rate values which correspond to the minimum current (4mA) and the
maximum current (20mA). Enter the two values in M56 and M57 separately.
Example A: flow rate range is 0-100m
3
/h. Just need to enter 0 in M56 and 1000 in M57.
Example B: flow rate range is -1000-0-2000m
3
/h. If flow direction is not an issue for the
application, user need to select 20-4-20mA mode in M55. Then, enter 1000 in M56 and 2000 in
M57. If flow direction is an issue, user need to select 0-4-20mA mode in M55. This means that the
current loop will output 0-4mA when flow rate is negative and 4-20mA when flow rate is positive.
Enter -1000 in M56 and 2000 in M57.
Users may need to check whether current loop is “calibration” by M58. The detailed operation is
given as below:
Firstly, press keys
, then by pressing keys and to call out
“0mA”,”4mA”,”8mA”, ”16mA”, ”20mA”, meanwhile, measure the current of current loop with a
higher accurate ampere meter. Lastly, calculate the difference between measuring value and
display value of flow meters. If the difference is over the allowed range, it is necessary to
re-calibrate the output of the current loop.
Users must open the debugging window before re-calibrating the analog output. The opening
way is as below:
Press
,input password “4213068”, then press again to open. The open is
only valid in this time power ON., and it will be automatically OFF when the password is invalid.
Press
into the standard status of 4mA output, and use the ampere meter to
measure the output current of current loop, meanwhile, press
and change the display value
of the flowmeter and watch the value of the ampere meter until it displays 4.00 which means the