|
In this dialog box, you can edit the specific parameters for the connection to Modbus PLCs.
|
Description
|
Default
|
Name of the Connection
|
This field displays the connection name which can be changed here.
|
|
Slave address
|
The slave address entered here will be transmitted in the Modbus frame.
|
9
|
Start Address 0
|
The starting address in the frame will be transmitted as specified.
|
Yes
|
Start Address 1
|
Some Modbus devices expect a starting address in the frame that is 1 less than the one you entered. The first address is 1.
|
No
|
Use Byte Swap
|
Swaps the bytes within a word
|
Off
|
Use Word Swap
|
Swaps the words within a double word (32 bits)
|
Off
|
Output Write
|
For writes, the Modbus opcode “Write Single Coil 05” is used or “Write Multiple Coils 15” or both
|
both
|
Register Write
|
For writes, the Modbus opcode “Write Single Register 06” is used or “Write Multiple Registers 16” or both
|
both
|
Register Bitwrite
|
Nearly all Modbus devices are supporting the register bitwrite using opcode 22. For devices without this an insecure version can be used: Read a register, modify a bit and write the register back.
|
Opcode 22
|
The slave address will be indicated in the item syntax.
Example: Id2.R2
For more details, see Modbus Item Syntax
|