ProSoft Technology CompactLogix MVI69E-MBS User Manual page 86

MVI69E-MBS ♦ CompactLogix™ Platform
Modbus Serial Enhanced Communication Module
Swap Code
Node Address
Modbus Function
MB Address in
Device
ProSoft Technology, Inc.
0,1,2,3 Defines if the data received from the Modbus slave is to be
ordered differently than received from the slave device. This
parameter is helpful when dealing with floating-point or other
multi-register values, as there is no standard method of storage of
these data types in slave devices. You can set this parameter to
order the register data received in an order useful by other
applications.
No Change (0)= No change is made in the byte ordering (ABCD
= ABCD)
Word Swap (1)= The words are swapped (ABCD= CDAB)
Word and Byte Swap (2) = The words are swapped, then the
bytes in each word are swapped (ABCD=DCBA)
Byte Swap (3) = The bytes in each word are swapped
(ABCD=BADC)
Note: Each pair of characters is a byte. Ex: AB and CD. Two
pairs of characters is 16-bit register Ex: ABCD.
1 to 255 Specifies the Modbus slave node address on the network to be
(0 = broadcast) considered. Most Modbus devices only accept an address in the
range of 1 to 247. If you set the value to zero, the command is a
broadcast message on the network. The Modbus protocol permits
broadcast commands for write operations. Do not use this node
address for read operations.
1,2,3,4,5,6,15,16 Specifies the Modbus function to be executed by the command.
These function codes are defined in the Modbus protocol.
1 – Read Coil Status (0xxxx)
2 – Read Input Status (1xxxx)
3 – Read Holding Registers (4xxxx)
4 – Read Input Registers (3xxxx)
5 – Force (Write Single) Coil (0xxxx)
6 – Force (Write Single) Holding Register (4xxxx)
15 – Preset (Write) Multiple Coils (0xxxx)
16 – Preset (Write) Multiple Registers (4xxxx)
0 to 65535 Specifies the register or digital point address offset within the
Modbus slave device. The MBS Master reads or writes from/to
this address within the slave.
Refer to the documentation of each Modbus slave device for their
register and digital point address assignments.
Note: The value entered here does not need to include the
"Modbus Prefix" addressing scheme. Also, this value is an offset
of the zero-based Modbus addressing scheme.
Example: Using a Modbus Function Code 3 to read from address
40010 in the slave, a value of '9' would be entered in this
parameter. The firmware (internally) adds a '40001' offset to the
value entered. This is the same for all Modbus addresses (0x, 1x,
3x, 4x).
Legacy Mode
User Manual
Page 86 of 159