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Proxy Ext (Server Boolean)

This is the proxy extension for either a ModbusServerBooleanPoint (BooleanPoint) or ModbusServerBooleanWritable (BooleanWritable). It contains information necessary information to poll (read) a status data value from a server Modbus device.
Figure 22.   Proxy Ext (Server Boolean) Properties
Image

You access these properties by expanding ModbusSlaveNetwork > ModbusSlaveDevice > Points in the Nav tree and double-clicking the ModbusServerBooleanPoint or ModbusServerBooleanWritable.

In addition to the standard properties (Status, Fault Cause and Enabled), these properties are unique to the Client Boolean proxy extension.

Property Value Description
Device Facets Config Facets window Defines the text to display for the Boolean values:

trueText configures the text to describe the state when the component returns true.

falseText configures the text to describe the state when the component returns false.

For example, you might want to set the facet trueText to display “ON” and the facet falseText to display “OFF.”

You view Facets on the Slot Sheet and edit them from a component Property Sheet by clicking the >> icon to display the Config Facets window.

Conversion drop-down list Selects the units to use when converting values from the device facets to point facets.

Default automatically converts similar units (such as Fahrenheit to Celsius) within the proxy point.

 NOTE: In most cases, the standard Default conversion is best.  

Linear applies to voltage input, resistive input and voltage output writable points. Works with linear-acting devices. You use the Scale and Offset properties to convert the output value to a unit other than that defined by device facets.

Linear With Unit is an extension to the existing linear conversion property. This specifies whether the unit conversion should occur on “Device Value” or “Proxy Value”. The new linear with unit convertor, will have a property to indicate whether the unit conversion should take place before or after the scale/offset conversion.

Reverse Polarity applies only to Boolean input and relay output writable points. Reverses the logic of the hardware binary input or output.

500 Ohm Shunt applies to voltage input points only. It reads a 4-to-20mA sensor, where the Ui input requires a 500 ohm resistor wired across (shunting) the input terminals.

Tabular Thermistor applies to only a Thermistor input point and involves a custom resistance-to-temperature value response curve for Type 3 Thermistor temperature sensors.

Thermistor Type 3 applies to an Thermistor Input point, where this selection provides a “built-in” input resistance-to-temperature value response curve for Type 3 Thermistor temperature sensors.

Generic Tabular applies to non-linear support for devices other than for thermistor temperature sensors with units in temperature. Generic Tabular uses a lookup table method similar to the “Thermistor Tabular” conversion, but without predefined output units.

Turning Policy Name drop-down list (defaults to Default Policy) Specifies the tuning policy to use for the proxy point.
Read Value read-only Reports the value read by the driver.
Write Value read-only Reports the last value to be written.
Poll Frequency drop-down list Configures how frequently the system polls proxy points.
Data Address drop-down list (defaults to Modbus) Specifies the address of the polled data item (prior to any offset address change as a result of using device-level Base Address), as a combination of the address format and the numerical address expressed in the selected format. The formats are:

Modbus

Hex

Decimal

For example, the following are all equivalent addresses:

  • Modbus, 40012
  • Hex, 0B
  • Decimal, 11.

 NOTE: If you use the Hex or Decimal format for most read-only points you need to specify the Reg Type property, to clarify whether you are using a holding register or an input register. 
Data Source read-only Identifies where the data came from, such as “Point Poll.”
Status Type drop-down list Selects between Coil or Input to define the type to read. Coil is the only valid option (the master cannot write to Modbus inputs). Selection is only necessary if the Data Address format is set to Hex or Decimal. The Modbus Address Format, if used, automatically sets this property value.
Out read-only Represents the point slot that contains the value to output.

Related Links

  • Points (Server) (Parent Topic)

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