Technical data

- Minimum scale velocity used with output: Enter the velocity to be equivalent to
the minimum frequency (i.e. 0Hz) of the frequency output. These values are only
enabled if the Content is set to Average flow velocity or Average sound velocity.
This property is disabled if Frequency outputs was cleared on the Startup Page.
Frequency Feedback
When frequency feedback is used, the frequency output signal is fed-back into the
processor so that error (due to frequency quantization) can be corrected. Frequency
quantization is what happens when the desired frequency cannot be exactly represented
(since infinite granularity cannot be achieved). The FreqXFeedbackCorrectionPcnt data
point specifies the percentage of the error fed back for correction. Typically, this
percentage is quite small since in most cases the error is quite small and fluctuates
"naturally" about zero. This point is editable via the Tools|Edit/Compare Configuration screen. It
is recommended that the FreqXFeedbackCorrectionPcnt not be modified from its default
value of 1%. Setting FreqXFeedbackCorrectionPcnt to zero, effectively disables frequency
feedback.
Configure digital input/outputs
Daniel 3810 Liquid Ultrasonic Flow Meters provide one digital input (referred to as DI1).
Digital Input 1 available indicator is based on the CPU Module's I/O board. The polarity of
the input is configured via the DI1IsInvPolarity data point as follows:
• FALSE - normal polarity (default setting), or
• TRUE - inverted polarity
The digital input is not configurable via the Daniel MeterLink Field Setup Wizard. It must be
configured via the Daniel MeterLink Tools|Edit/Compare Configuration. The value of the input is
accessible via the DI1 data point.
Digital Input calibration
The IsDI1 UsedForCal specifies whether digital input 1 (DI1) is used for general purpose
(when set to FALSE) or for synchronizing calibration (when set to TRUE). If used for
calibration, the polarity is determined by the IsDI1ForCalActiveLow data point select one
of the following:
• FALSE - general purpose (default setting), or
• TRUE - for synchronizing calibration
The IsDI1ForCalActiveLow data point specifies the polarity for digital input 1 (DI1) when it
is configured (via IsDI1UsedForCal) for use in synchronizing a calibration. See also
IsDI1ForCalStateGated.
• FALSE = Cal Active High
• TRUE = Cal Active Low (default)
The IsDI1ForCalStateGated data point specifies the calibration gating for digital input 1
(DI1) when it is configured (via IsDI1UsedForCal) for use in synchronizing a calibration.
When FALSE, the calibration is started/stopped via an inactive->active edge; when TRUE,
Daniel Liquid Ultrasonic Flow Meters calibration and configuration parameters
48 Daniel 3810 Series Operations Manual