SMC Networks 1560 user manual Modbus Plus Port Functionality, Modbus Plus Communications

Chapter 2 — Modbus Plus Port Functionality

Contents

2 Modbus Plus Port Functionality

2.1Modbus Plus Communications

The 1560-MBP Modbus Plus card supports the Modbus Plus protocol using proprietary technology licensed from Schneider Automation. With the Modbus Plus capability, the module is able to communicate data from Allen-Bradley SCANport compatible devices to a Modbus Plus host PLC, and vice-versa.

The following discusses the functional capabilities of the 1560- MBP card.

2.1.1 Supported MSTR Programming Commands

The 1560-MBP uses several of the available MSTR ladder logic commands to transfer data when using a Modicon PLC. These are overviewed below:

Read Data: The following types of data read commands are supported:

MSTR Type 2 Read Data

This command reads data from any place within the Modbus Register map. This command allows a Modbus host to selectively read data from the 1560-MBP as required for the application.

MSTR Type 6 Read Global Data

This command gets data from the Global Data being sent from the 1560-MBP. The 1560-MBP returns 2 to 10 words of Global data. This is the fastest method of reading values from the MBP.

Write Data: The following data write commands are supported:

MSTR Type 1 Write Data

This command writes data to any place within the 1560- MBP Modbus Register map. This command can be used to selectively write configuration values to the SCANport device. In addition, if the Global Data Command Enable dip switch is disabled, this command can be used to write to the SCANport Control and Reference words (Modbus addresses 40001 to 40010).

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