Rate Row Edit: Input tab

Input Coordinates

Enter the coordinate values for the pulse input accumulator.

Poll Group

(Pulse input data) A text string that may consist of multiple comma- separated values to define the frequency poll groups to which the point belongs.

For further information, refer to volume 2 of the RealTime Administrator documentation.

Input Type

Select (...) and select the data type of the pulse input accumulator.

Roll-over value

Enter the roll-over value.

Accumulators continue to register a count until a certain value is reached. The accumulator then resets, like a car odometer, and starts counting again. Enter this value, plus one, in the Roll-over value field.

For example, if the roll-over occurs at 999,999, then the value should be 1,000,000.

When Instrument Fail Check is selected, a telemetry pulse input value that is negative, or equal or greater than the configured Roll-over value is considered as an instrument failure.

Time between rate calculations (sec)

Enter the minimum length of time (in seconds) that should elapse between rate calculations. The lower the rate, the greater this time should be in order to increase rate calculation accuracy.

Meter Factor

Enter a meter factor value to help correct devices that are consistently inaccurate by the same percentage.

The number entered is multiplied by both the current accumulated value and the rate calculated from the change in pulse input accumulation. The Meter Factor is usually very close to 1.

The Meter Factor field is only applicable for rate points whose Source of Data as configured on the Main tab is either Pulse input or Pulse & Analog.

Input Type

Select (...) and select the data type of the pulse input accumulator.

Input Coordinates

Enter the coordinate values for the pulse input accumulator.

Poll Group

(Analog input data) A text string that may consist of multiple comma- separated values to define the frequency poll groups to which the point belongs

For further information, refer to volume 2 of the RealTime Administrator documentation.

Convert raw to EGU

Select to convert the inputs from this point to engineering units (EGUs).

An analog field device acquires its data as a raw instrument electrical value and transfers the value to its remote. At the remote, this value is changed into a digital value based on the communication protocol used. For example, in a certain protocol, the signal from a pressure controller that starts as an amperage between 4 and 20 mA is changed to a string of bits that represents a number between -4096 and+4095.Usually this raw number needs to be converted to EGUs (for example, barrels per hour). Sometimes the remote receives the value in EGUs, in which case no conversion is necessary. Refer to your remote’s documentation to see if this is the case for your remotes.

Minimum (raw)

Enter the instrument’s lower raw operating limit.

The EGU range represents the range of rate values expected for the point. This range should be set regardless of whether or not the rate is telemetry (an analog input), or calculated based on pulse counts over time (a pulse input).

Maximum (raw)

Enter the instrument’s upper raw operating limit.

The EGU range represents the range of rate values expected for the point. This range should be set regardless of whether or not the rate is telemetry (an analog input), or calculated based on pulse counts over time (a pulse input).

Exception Deadband

Enter the amount by which an acquired value must change before the value is sent to the host.

This field provides a report by exception method of acquiring data rather than acquiring data with every Omnicomm scan. Analog data changes constantly with the fluctuations in process conditions. Instead of constant updates of tiny changes, which congest the lines, the data is transferred to the host only when a specified deadband region has been exceeded. This method can only be used if the remotes support analog reporting by exception. Since the decision of whether or not to upload the data is made by the remote, the deadband value is downloaded to the remote in raw units. The exception deadband indicates the amount by which an acquired value must change before the value is sent to the host. For example, a deadband value of 10 means that only values at least 10 raw counts higher or lower than the last value sent to the host are transferred.

Rate Subtype

Select the rate subtype.

A telemetry rate point acquires data in different media such as oil, water, or gas. The raw rate value that is adjusted to an engineering unit value may require additional adjustments due to various parameters involved; therefore, algorithms are provided to compensate for different media. The Rate Subtype selection indicates which algorithm to use.

The choices are:

• Linear. There is no compensation or further scaling when the flow rate is obtained.

• Liquid. The flow rate is obtained by taking the square root of the rate value.

• Gas. The gas measurement requires adjustments for the effects of temperature and pressure. You must configure the fields in the Gas Rate Subtype area.

Cutoff

This section is used to set low or high cutoff values for rate points, with the aim of avoiding false readings from remotes. If the host receives a value that is below or above the low or high cutoff value, respectively, it discards the value and uses the Administrator-defined "replacement" value.

Note: The Low Cutoff Limit and High Cutoff Limit values must be greater than the Minimum (EGU) value, and less than the Maximum (EGU) value, respectively.

For further information, refer to Analog Cutoff.

Pressure Analog Point

Select (...) and select the associated pressure analog record for this rate point from the Analog Select dialog box.

Temperature Analog Point

Select (...) and select the associated temperature analog record for this rate point from the Analog Select dialog box.

Scaling Factor

(Gas)

If you are scaling a gas flow rate, enter the gas scaling factor. The value is calculated by the following formula:

where:

• k is the gas scaling factor.

• t is the temperature (measured in °F).

• p is the pressure (measured in psi).

• r is the uncorrected flow rate.

  The gas scaling factor (k) should be adjusted until the displayed rate value is equal to a testing instrument’s rate value at that point.

Scaling Factor (Water)

If you are scaling a water flow rate, enter the water scaling factor that converts the raw input value to the appropriate EGU value.

Processing Deadband Enable

Select to associate the point with a processing deadband.

For further information, refer to Processing Deadband enhancement.

Processing Deadband

Enter the processing deadband that the system uses to determine whether or not it should process a new value.

For further information, refer to Processing Deadband enhancement.

Trend Indicator Enable

Select the checkbox to enable the Trend Indicator for the rate point.

Note: When the Trend Indicator is enabled for a point, the trend indicator value is set to 0. The current value for the Trend Indicator is stored in the TrendIndicator.Value field of the rate record.

For more information about how this value is calculated, refer to Trend Indicator.

High Speed Coefficient

Enter the value for the high speed coefficient. This is typically a float number between 0 and 1.

For more information about how this value is used in the calculation of the trend indicator value, refer to Trend Indicator.

Low Speed Coefficient

Enter the value for the low speed coefficient. This is typically a float number between 0 and 1.

For more information about how this value is used in the calculation of the trend indicator value, refer to Trend Indicator.

Scaling Factor

Enter the value for the desired scaling factor to be applied to the trend indicator value.

For more information about how this value is used in the calculation of the trend indicator value, refer to Trend Indicator.

Trend Indicator Image Set

Enter or select the name of the trendIndicatorImageSet record used to specify the collection of parameters for which an image will be presented as the trend indicator for this point.