Input Properties

The Inputs properties section of the Flow Run tab is common to all three flow run types. You can configure these properties directly in Geo SCADA Expert, or read the configuration into the Geo SCADA Expert database (see Configure or Read the Flow Run Configuration).

Use the following fields within the Inputs section of the Flow Run tab to define the properties that are associated with the flow calculation’s input values:

Flow Run ID

Enter the flow run identification string that identifies the flow run. The Flow Run ID is alpha-numeric for standard Realflo and numeric for PEMEX Realflo. Flow computer versions earlier than 6.00 accept a string up to 16 characters long. With flow computer versions 6.00 or newer, you can enter a string up to 32 characters long.

The Flow Run ID is not supported in flow computers pre-version 6.00. Realflo will not read or write the Flow Run ID when an older flow computer is detected.

Input Units

Select the units of measurement of the input values for the flow run. Inputs may be measured in different units than the calculated results. You can use the units that are convenient to you for measuring inputs. The units available are determined by the flow run type:

For more information about a particular unit, select the relevant entry in the table above.

Low Flow Events

Select whether to log or ignore flow events that occur for the flow run. You can select the following from the combo box:

Hysteresis Units

Define how the hysteresis is configured for the High-High, High and Low alarms. The setting defines the level at which alarms are cleared when the input variable reading returns to a non-alarm state. This setting reduces nuisance alarms around the alarm threshold.

Select one of these options:

NOTE: When the AGA-7 flow calculation is used the alarm hysteresis is represented as a pulse input frequency. The pulse input is independent of the hysteresis units selection.

For Liquid flow calculation this is only applied to Static Pressure Properties and Temperature Properties values.

For Water flow calculations this in only applied to Temperature Properties values.

Sensor Fail Value

Use this property to define the value that is used as the live input value when communication with a sensor is interrupted. You can select the following from the list:

For flow computers prior to version 6.70, the value on sensor fail is always set to Use Last Known Good Value.

Run Direction

This allows you to indicate the direction of flow, forward or reverse, for a meter run. The flow computer calculates flow rates and accumulates flow volumes for one flow direction only for each flow run configured. If you want to calculate flow rates and accumulate volume for another flow direction you need to configure a second flow run, using the same run parameters, but with an opposite flow direction setting.

Select one of the following from the combo box:

Forward by Value

Select this option if the flow direction is forward when the value from a differential pressure (DP) sensor is positive or the mass flow rate value from a Coriolis meter is positive.

Reverse by Value

Select this option if the flow direction is reverse when the value from a differential pressure (DP) sensor is negative or the mass flow rate value from a Coriolis meter is negative. When the flow direction is reverse the flow computer calculates flow rates and accumulates volumes for the flow run.

Forward by Status

Select this option if the flow direction is forward when the Flow Direction Register has a value of 1 (ON) and the On Indication value is set to Forward. When the flow direction is forward the flow computer calculates flow rates and accumulates volumes for the flow run.

Reverse by Status

Select this option if the flow direction is reverse when the Flow Direction Register has a value of 1 (ON) and the On Indication value is set to Reverse. When the flow direction is reverse the flow computer calculates flow rates and accumulates volumes for the flow run.

Direction Status Register

Specify which register indicates the forward or reverse flow direction status. You can use valid registers for the flow computer controller for this setting. The default register is 1. This property is unavailable if the Run Direction option is set to Forward/Reverse by Value. This property is unavailable in GOST mode flow computers.

This field is unavailable for use if the Flow Run is located on a Realflo controller on which the Firmware Type is set to x70 (see Specify the Firmware Type).

Direction Status Object Name

This Object Name field applies instead of the Register field if the Flow Run is located on a Realflo controller on which the Firmware Type is set to x70 (see Specify the Firmware Type). Specify the name of the object that indicates the forward or reverse flow direction status. This field is unavailable if the Run Direction option is set to Forward/Reverse by Value. This field is unavailable in GOST mode flow computers.

Ensure that the name that is specified in this field exactly matches that of the relevant object that exists in the Realflo controller. The name can be a maximum of 32 characters long. It has to start with a letter or underscore character (_) and can only contain alphanumeric characters and underscores (_). It cannot contain consecutive underscore characters and is not case sensitive.

On Indicates

This field allows you to select either Forward or Reverse for the status register value. The default is Forward. The property is unavailable in GOST mode. The property is unavailable if the the Run Direction option is set to Forward/Reverse by Value.

The properties that you configure in the Inputs section are used for the differential pressure, static pressure, temperature inputs and the pulse input frequency when AGA-7 calculations are used.

High-High Alarm

Use to specify whether high-high alarms are used for input variables to the flow calculation. You configure the actual alarm criteria in the individual input sections.

High Alarm

Use to specify if high alarms are used for input variables to the flow calculation. The high alarm conditions are set in the individual input sections.

Low Alarm

Use to specify if low alarms are used for input variables to the flow calculation. The low alarm conditions are set in the individual input variable tabs.

Values in Alarm

Use to set the value for the input when the input is in an alarm condition. This is a global setting for input variables using alarms.

Coil Alarm Output Indication

Use to enable the alarm output indication to use standard Modbus coil registers. When enabled, the alarm output indication can be set for differential pressure, static pressure, temperature and turbine measurement inputs.

For Realflo version 6.79.1 this parameter is set to Enabled and the control is unavailable.

Further Information

Measurement Units.

For more detailed information on these properties, see the documentation provided with the Realflo application.


Disclaimer

Geo SCADA Expert 2020