ProSoft Technology MVI69E-MBS - Manual (Page 58)

MVI69E-MBS Configuration MVI69E-MBS ♦ CompactLogix Platform
User Manual Communication Module
Page 58 of 162 ProSoft Technology, Inc.
January 6, 2014
3.2.3 Modbus Port x Commands
The Modbus Port x Commands section defines the master command list
specifications for a Master port. The information in this section applies to both
Port 1 and Port 2.
In PCB’s tree view, double-click the "Modbus Port x Commands” icon.
In order to interface the MVI69E-MBS module with Modbus slave devices, you
must create a command list. The commands in the list specify the slave device to
be addressed, the function to be performed (read or write), the data area in the
device to interface with and the registers in the internal database to be
associated with the device data.
The Master command list supports up to 250 commands. The command list is
processed from top (Command #0) to bottom.
Read commands are executed without condition. You can set write commands to
execute only if the data in the write command changes (Conditional Enable). If
the register data values in the command have not changed since the command
was last issued, the command is not executed. You can use this feature to
optimize network performance.
The MBS Modbus Master (and Slave) communication drivers support several
data read and write commands. When a command is configured, the type of data
(bit, 16-bit integer, 32-bit float, etc), and the level of Modbus support in the slave
equipment needs to be considered. For information on floating-point support,
please See Floating-Point Support on page 125.
Parameter Value Description
Enable 0 to 4 This field defines whether the command is to be executed
and under what conditions.
Disabled (0) = The command is disabled and is not
executed in the normal polling sequence.
Continuous (1) = The command is executed each scan of
the command list if the Poll Interval (see below) is set to
zero. If the Poll Interval is set to a nonzero value, the