Emerson Model 1700 User Manual

Pulses/Unit

A user-specified number of pulses represents one flow unit

Units/Pulse

A pulse represents a user-specified number of flow units

2.

Set additional required parameters.

•

If you set Frequency Output Scaling Method to Frequency=Flow, set Rate Factor and
Frequency Factor

.

•

If you set Frequency Output Scaling Method to Pulses/Unit, define the number of pulses
that will represent one flow unit.

•

If you set Frequency Output Scaling Method to Units/Pulse, define the number of units
that each pulse will indicate.

Calculate frequency from flow rate

The Frequency=Flow option is used to customize the frequency output for your application
when you do not know appropriate values for Units/Pulse or Pulses/Unit.

If you specify Frequency=Flow, you must provide values for Rate Factor and Frequency Factor:

Rate Factor

The maximum flow rate that you want the frequency output to report.
Above this rate, the transmitter will report A110: Frequency Output Saturated.

Frequency
Factor

A value calculated as follows:

FrequencyFactor =

x N

RateFactor

T

where:

Factor to convert selected time base to seconds

N Number of pulses per flow unit, as configured in the receiving device

The resulting Frequency Factor must be within the range of the frequency output (0 to
10,000 Hz):

•

If Frequency Factor is less than1 Hz,reconfigure the receiving device for a higher
pulses/unit setting.

•

If Frequency Factor is greater than 10,000 Hz, reconfigure the receiving device for a
lower pulses/unit setting.

If Frequency Output Scale Method is set to Frequency=Flow, and Frequency Output Maximum Pulse Width is set
to a non-zero value, Micro Motion recommends setting Frequency Factor to a value below 200 Hz.

Example: Configure Frequency=Flow

You want the frequency output to report all flow rates up to 2000 kg/min.

The frequency receiving device is configured for 10 pulses/kg.

Solution:

Integrate the meter with the control system

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