Proxy Ext (Client Enum Bits)

This is the proxy extension for either a ModbusClientEnumBitsPoint (Enum Bits Point) or ModbusClientEnumBitsWritable (Enum Bits Writable). It supports reading both Modbus holding register or input register values, and extracting bits specified by the Beginning Bit and Number of Bits properties. The combination of these bits is the point’s value, as a StatusEnum. The writable variant writes the point’s (ordinal, integer) value into the raw register bits at the specified Beginning Bit relative position. Like other Modbus proxy points, both point-level or device-level polling is supported.
Figure 13.   Modbus Client Enum Bits properties
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You access these properties by expanding ModbusAsynNetwork > ModbusAsyncDevice > Points in the Nav tree and double-clicking ModbusClientEnumBitsPoint or ModbusClientEnumBitsWritable.

In addition to the standard properties (Status, Fault Caues and Enabled), these properties are specific to the Client Enum Bits proxy extension:

Property Value Description
Facets — Boolean trueText (default) or falseText Facets contain additional data applied to input and output values.
  • trueText is the text to display when output is true
  • falseText is the text to display when output is 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.

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 additional properties 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. 
Absolute Address additional properties Differs from Data Address only if using device Base Addresses. It is the sum of the Data Address value and the associated Base Address value (as configured in the parent Modbus device). This is the actual address that will be used when polling for this discrete data point from the actual Modbus device. The address of the polled data item is a combination of:
  • Address Format — either Modbus (default), Hex, or Decimal.
  • Address — numerical address, expressed in the selected Data Address format.
Data Source read-only Identifies where the data came from, such as “Point Poll.”
Reg Type drop-down Selects the type of register.
Beginning Bit a number from 0 to 15 Identifies the bit in the register where status information starts.
Number of Bits number from 1–6 Defines the number of bits used for this enum point.
Out read-only Represents the point slot that contains the value to output.