Optimizing how Modbus devices are polled - Modbus 4.1

Modbus Plugin Guide 4.1

series
Modbus 4.1
revised_modified
2020-05-06

To poll the properties of Modbus devices in the most efficient way possible, you should enable range optimization.

What you should know

When range optimization is enabled, a read request can be set to poll multiple properties on a Modbus device. For example, if you have a device with 100 coils, instead of making 100 requests that read one coil each, you can make one request to read 100 coils.

Procedure

  1. From the Config Tool home page, open the Plugins task.
  2. Select the Modbus plugin role from the entity browser, and click on the Entities tab.
  3. In the Advanced settings section, move the Optimize read requests slider to ON.
  4. In the Coil / Discrete Inputs per read field, enter the number of properties to be polled per read.
    The minimum value is 1. The maximum value is 2000.
  5. In the Holding / Input registers per read field, enter the number of properties to be polled per read.
    The minimum value is 1. The maximum value is 125.
  6. Click Apply.