ModMaster Manual v3.14 - 5.1. Defining commands
You can use the Define Command page to define and send Modbus commands.
Select the required type of command from the Command Type drop-down list, and enter/select values as necessary.
When you have entered a command definition, you can click the Send button to send the command to the slave. The result of sending the command will be displayed in the page.
If you want to save the command definition, enter a unique name for the command in the Name field and click the Save button. All saved command definitions are listed in the Command table.
You can provide a description of the command in the Description field. ModMaster displays the description, but does not use it in any other way. It is purely for your benefit, to remind you of what the command is used for.
The Reset button will restore the values to their last saved state.
There are three kinds of command types in the Command Type drop-down list:
Custom command. This option enables you to define and send non-standard Modbus commands, and is described in the Custom commands section.
Send raw data. This option enables you to send arbitrary data to the slave, and is described in the Sending raw data section.
Standard commands. These are standard Modbus commands, which are described in the Standard commands section.