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Contents
2
Modbus Plus Port Functionality
2.1
Modbus 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).
Chapter 2 — Modbus Plus Port Functionality
