Reading a specific bit range of a Modbus data point - Modbus 4.1

Modbus Plugin Guide 4.1

series
Modbus 4.1
revised_modified
2020-05-06

You can create a property on a Modbus device by polling a single bit or bit range of a data point.

What you should know

  • The only data points that you can read a specific bit range for are input registers or holding registers. Coils and discrete inputs have a single bit.
  • The plugin interprets the ordering of bytes within a Modbus register as big-endian. In the user interface, bit 0 represents the least significant bit and bit 15 represents the most significant bit.

Procedure

  1. From the Config Tool home page, open the Plugins task.
  2. Select a Modbus device from the entity browser, and click on the Properties tab.
  3. In the Data Point section, select and input or holding register, and click the Edit data point of Modbus device () button .
  4. From the Type list, select Bit range.
    The Bits fields are displayed.
  5. In the Bits fields, enter value of the bits that you want to read.
  6. Click Save, and then click Apply.