The accuracy of the current loop output is better than 0.1%. It can be configured to different
mode, such as 4-20mA mode, 0-20mA etc. Mode selection can be made in menu M55.
Refer to the next chapter for details on M55.
In order to use the 4-20mA output function, you need not only select the mode to be
4-20mA in
M55, but also set the flow rate values which correspond to the minimum current (4mA) and
the
maximum current (20mA). Enter the two values in M56 and M57.
Example A: flow rate range is 0-500m3/h. Just enter 0 in M56 and 500 in M57.
Example B: flow rate range is -500-0-1000m3/h. If flow direction is not an issue for you, you
may select 20- 4-20mA mode in M55. Then, enter 500 in M56 and 1000 in M57. If flow
direction is an issue, you may 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 -500 in M56 and 1000 in M57.
You may need to calibrate and test the current loop output before using it. Just go to menu

M58 and do the following:

First, connect an ammeter to the current loop output.
Press MENU 5 8 , then ENT to enter into menu M58.
Use
/+ and /- to display "0mA", "4mA", "8mA", "16mA", "20mA"
orderly, record the corresponding reading on the ammeter. Calculate the differences
between the readings and the selected ones. For instance, when 4mA is selected, the
actual output current shown on the ammeter is 4.01mA. Then, the difference is 0.01mA.
If the differences are not within tolerance, calibrate the current loop
The present current loop output is displayed in Window M59. It changes along with flow
rate change.