Density Properties (Liquid Flow Run)

The fields within this section of the Liquid tab display those properties that are associated with Density measurement.

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).

• Input Type—Select the required input type. The options vary, depending on the type of Realflo controller on which the Flow Run is located. The options are as follows if the Flow Run is located on a Realflo controller on which the Firmware Type is set to x70:
  • Coriolis Meter
  • Constant
  • Database Object.

  If the Flow Run is located on another other type of Realflo controller, the options are:

  • Telepace Integer
  • Float
  • Raw Float
  • ISaGRAF integer
  • Coriolis Meter
  • Constant.

  The availability of the fields in the rest of the Density section varies, depending on the Input Type.

• Input Register—This field is available for Input Type options other than Constant.

  With an Input Type other than Coriolis Meter, use this field to define the address of the register in the Flow Computer I/O database that contains the density properties. Valid values are in the ranges 30001 to 39998 and 40001 to 49998.

  When using Realflo 6.95 or above, if the Input Type is set to 'Coriolis Meter', use this field to specify which Coriolis meter is to provide the input value. Enter a value in the range 1 to 10 inclusive, where the number corresponds to the number of the Flow Run on which the Coriolis meter is configured (and, as such, the Flow Run that will poll the Coriolis meter). For example, enter 2 to use the Coriolis meter that is configured on Flow Run 2.

  This field is unavailable for use when the Input Type is set to Database Object.

• Input Object Name—This Input Object Name field applies instead of the Input Register field when the Input Type is set to Database Object. Use to specify the name of the density input object in the Flow Computer I/O database.

  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.

• Constant Value—Only available when the Input Type is set to Constant. Specify the value of the constant.
• Raw Input at Zero Scale—Specify the value read from the sensor when the sensor is at zero scale. Valid values depend on the input type. The default value is 0.

  This field is available for options other than Database Object, Float, Coriolis Meter and Constant.

• Raw Input at Full Scale—Specify the value read from the sensor units when the sensor is at full scale. Valid values depend on the input type. The default value is 32767.

  This field is available for options other than Database Object, Float, Coriolis Meter and Constant.

• Engineering Input at Zero Scale—Specify the density that corresponds to the zero scale input. Valid values depend on the input type.

  This field is available for options other than Coriolis Meter and Constant.

• Engineering Input at Full Scale—Specify the density that corresponds to the full-scale input. Valid values depend on the input type.

  This field is available for options other than Coriolis Meter and Constant.

• Default Value—Set the value for the input variable to use when any of the following conditions are met:
  • The Sensor Fail Values option in the Input Properties section is configured to Use Configured Defaults.
  • When alarms are enabled and the Values in Alarm option on the Input Properties section is set to Use Default Values.

  If you select the Constant input type, this field is unavailable.

The input alarms section of the Density section allows you to set the alarm thresholds for alarm types that have been enabled in the Inputs section.

Use the following to configure alarm limits in the Density section:

• High-High Alarm Threshold—Set the high-high alarm threshold value for the density. A valid entry value is any value within the density range that is higher than or equal to the value of High Alarm Threshold. The default is the Density at Full Scale for analog inputs, or the Upper Operating Limit for sensors. The default value is 500. This control is enabled if Use High-High Alarm option is enabled on the Input Properties section, otherwise this control is unavailable.
• High Alarm Threshold—Set a high alarm threshold for the density. A valid entry value is any value within the density range that is higher than the value of Low Alarm Threshold, and is lower than or equal to the value of High-High Alarm Threshold. The default value is 500. This control is enabled if Use High Alarm option is enabled on the Input Properties section, otherwise the control is unavailable.
• Low Alarm Threshold—Set a low alarm threshold for the density value. A valid entry is any value in the density that is lower than the value of High Alarm Threshold. The default value is 0. This control is enabled if the Use Low Alarm option is enabled on the Input Properties section, otherwise the control is unavailable.
• Alarm Hysteresis—Set the hysteresis value for each configured alarm type. The hysteresis setting determines at what level alarms are cleared when the input variable reading returns to a non-alarm state. This setting reduces nuisance alarms around the alarm threshold. Enter a value in the full-scale range of the input variable.