Low-Flow Cutoff (Cutoff); Analog Output Programming (Aoutpr) - Ametek DDMC Instruction Manual

DDMC Analog Input Process Meter / Controller
Changing the Volume from Gallons to Liters
In the above graphic, entering the 48" for the diameter
and 120" for the length of the round horizontal tank,
the meter automatically calculates that the volume of
the tank is 940.02 gallons.
1. Convert gallons to liters
1 US gallon = 3.7854 L
940.02 gal = 3558.4 L
2. Go to the Setup menu and change the
decimal point to 1 decimal.
3. Go to the Program – Scale menu and press
Enter until dis 2 is shown on the main
display.
4. Press Enter and change the display 2 value to
3558.4.
5. The meter is now displaying the volume in
liters.
Note: The display can be scaled to display the volume
in any engineering units.
Another way to display the volume in liters is to enter
the dimensions in cm. The meter automatically
calculates the volume in liters.

Low-Flow Cutoff (CutofF)

The low-flow cutoff feature allows the meter to be
programmed so that the often-unsteady output from a
differential pressure transmitter, at low flow rates,
always displays zero on the meter.
The cutoff value may be programmed from 0 to
999999. The meter will display zero below the cutoff
value. Programming the cutoff value to zero disables
the cutoff feature.
Analog Output Programming
(AoutPr)
The Analog Output Programming menu is used to
program the behavior of the 4-20 mA output. The
following parameters and functions are programmed
in this menu:
1. Source: Source for generating the 4-20 mA
output (e.g. PV)
2. Overrange: Analog output value with display in
overrange condition
3. Underrange: Analog output value with display in
underrange condition
4. Break: Analog output value when loop break is
detected
5. Max: Maximum analog output value allowed
regardless of input
6. Min: Minimum analog output value allowed
regardless of input
7. Calibrate: Calibrate the internal 4-20 mA source
reference used to scale the 4-20 mA output
Analog Output Source
The source for generating the 4-20 mA output may be
assigned to the process variable, maximum or
minimum value reached by the process, one of the
set points, or the Modbus PV input.
Analog Output Calibration
To perform the analog output calibration, it is
recommended to use a milliamp meter with a
resolution of at least 0.1 µA to measure the output
current. The values saved internally during this
procedure are used for scaling the 4-20 mA output in
the Setup menu.
Analog Output Calibration
Procedure
1. Wire the DDMC 4-20 mA output to a current loop
that includes a power supply (internal or external
12 to 24 VDC), and the mA input on the digital
meter. See Figure 20. 4-20 mA Output
Connections on page 17 for details.
2. Turn on all devices. Allow for a 15 to 30 minute
warm-up.
3. Go to the Advanced Features menu, and
navigate to the Analog Output Programming
(AoutPr)/Calibration (Calib) menu and press
Enter.
4. The display will show 4 nmA. The DDMC mA
output should now be close to 4 mA. Press Enter
and the display will show 04.000. Enter the actual
value read by the digital mA meter and press
Enter.
5. The display will show 20 nmA. The DDMC mA
output should now be close to 20 mA. Press
Enter and the display will show 20.000. Enter the
actual value read by the digital mA meter and
press Enter.
6. The meter will now calculate the calibration
factors and store them.
7. Press Menu to exit and return to Run mode.
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Instruction Manual