Modbus Addressing Versus SIXNET Addressing

 

Many SIXNET products can be configured to send and/or receive Modbus protocol. When configuring a hardware device or HMI software to send Modbus commands to SIXNET hardware, specify the appropriate "SIXNET as Modbus" data type number and starting Modbus address. Refer to the "SIXNET as Modbus" columns in the chart below. When configuring a SIXNET programmable station to send Modbus commands (using I/O Transfers) to a non-SIXNET device, you can specify a Modbus data type number and an appropriate starting Modbus address that is anywhere within the "Maximum Modbus Address Range". If a SIXNET programmable station will be sending Modbus commands to another SIXNET station configured to respond to Modbus protocol, specify the appropriate "SIXNET as Modbus" data type number and starting Modbus address. Refer to the "SIXNET as Modbus" columns in the chart below.

 

Notes:

 

 

 

"Generic Modbus"

"SIXNET as Modbus"

Modbus Data

Maximum Addressing

Modbus

Equivalent SIXNET

Type Number

Type # and Address Range

Address Range

Addresses

1 (Discrete In) 

1:0001 … 1:19999

 1:0001 … 1:19999

DI:0 … DI:19998

0 (Discrete Out)

0:0001 … 0:19999

0:0001 … 0:19999

DO:0 … DO:19998

3 (Analog In)

 3:0001 … 3:31999

3:0001 … 3:2999

AI:0 … AI:2998

3 (Short Integer In)

3:0001 … 3:31999

3:3001 … 3:4999

AI:0 … AI:1998

4 (Analog Out)

4:0001 … 4:31999

4:0001 … 4:2999

AO:0 … AO:2998

4 (Short Integer Out)

4:0001 … 4:31999

4:3001 … 4:4999

AO:0 … AO:1998

 

 

 

 

   

 

When Using Register Pairs (two 16 bit registers):

3 (Long Integer In)

3:0001 … 3:31999

3:5001 … 3:6999

LI:0 … LI:998

4 (Long Integer Out)

4:0001 … 4:31999

4:5001 … 4:6999

LO:0 … LO:998

3 (Floating Point In)

3:0001 … 3:31999

3:7001 … 3:9999

FI:0 … FI:1498

4 (Floating Point Out)

4:0001 … 4:31999

4:7001 … 4:9999

FO:0 … FO:1498

 

 

 

 

   

When Using Daniel Extensions (one 32 bit register):

3 (Long Integer In)

DLI:0001 … DLI:31999

DLI:0001 … DLI:1999

LI:0 … LI:1998

4 (Long Integer Out)

DLO:0001 … DLO:31999

DLO:0001 … DLO:1999

LO:0 … LO:1998

3 (Floating Point In)

DFI:0001 … DFI:31999

DFI:0001 … DFI:2999

FI:0 … FI:2998

4 (Floating Point Out)

DFO:0001 … DFO:31999

DFO:0001 … DFO:2999

FO:0 … FO:2998

   

   

Examples:       Modbus data address 1:0001 equates to SIXNET discrete input 0.

Modbus data address 1:0006 equates to SIXNET discrete input 5.

 

Modbus data address 3:0001 equates to SIXNET analog input 0.

Modbus data address 3:0003 equates to SIXNET analog input 2.

 

Modbus data address 0:0001 equates to SIXNET discrete output 1.

Modbus data address 0:0006 equates to SIXNET discrete output 5.

 

Examples for floating point and long integer I/O are shown in the help topics for those I/O types.

 

See Also: Reading and Writing Long Integer and Floating Point Values