Dynasonics TFX Ultra Transit Time Flow Meters - Manual (Page 60)

Flow Filter Sensitivity allows configuration of how fast the Flow Filter Damping will adapt in the positive direction.
Increasing this value allows greater damping to occur faster than lower values. Adaptation in the negative direction is not
user adjustable.
Bad Data Rejection is a value related to the number of successive readings that must be measured outside of the Flow Filter
Hysteresis or Flow Filter MinHysteresis windows before the flow meter will use that flow value. Larger values are entered into
Bad Data Rejection when measuring liquids that contain gas bubbles, as the gas bubbles tend to disturb the ultrasonic signals
and cause more extraneous flow readings to occur. Larger Bad Data Rejection values tend to make the flow meter more
sluggish to rapid changes in actual flow rate.
Output Tab
The entries made in the Output tab establish input and output parameters for the flow meter. Select the appropriate function
from the pull-down menu and press Download. When a function is changed from the factory setting, a configuration error
1002 will result. This error will be cleared by resetting the flow meter microprocessor from the Communications/Commands/
Reset Target button or by cycling power on the flow meter. Once the proper output is selected and the microprocessor is
reset, calibration and configuration of the modules can be completed.
Do w n l o a d Ca n c el F i l e Op en . . . F i l e Sa v e. . .
S y s t e m C o n f i g u r a t i o n
Display Basic Flow Filtering Output Security
Co n tr o l Ou tp u ts Channel 2:
50 Off < Gal/M
350
On> Gal/M
Mode:
F l o w
Control 1
Mode:
No n e
Control 2
4-20m A / F r eq u en c y Channel 1:
0 Flow at 4mA / 0Hz: Gal/M
400 Flow at 20mA / 1KHz: Gal/M
Calibration/Test
Test
Calibration
4 m A
20 m A
32
3837
Test 4
Figure 43: Output tab
Channel 1 – 4-20 mA Configuration
OTE:
N
The 4-20 mA Output menu applies to all flow meter versions and is the only output choice for Channel 1.
The channel 1 menu controls how the 4-20 mA output is spanned for all models and how the frequency output is spanned for
the flow only model.
The Flow at 4 mA / 0 Hz and Flow at 20 mA / 1000 Hz settings are used to set the span for both the 4-20 mA output and the
0…1000 Hz frequency output on the flow only versions.
The 4-20 mA output is internally powered (current sourcing) and can span negative to positive flow/energy rates. This output
interfaces with virtually all recording and logging systems by transmitting an analog current that is proportional to system
flow rate. Independent 4 mA and 20 mA span settings are established in firmware using the flow measuring range entries.
These entries can be set anywhere in the –40…40 fps (–12 …12 mps) range of the instrument. Resolution of the output is
12-bits (4096 discrete points) and can drive up to a 400 Ohm load when the meter is AC powered. When powered by a DC
supply, the load is limited by the input voltage supplied to the instrument. See Figure 23 for allowable loop loads.
BASIC TAB
Page 60 March 2014