I-7530A-MR Modbus RTU to CAN
Converter User’s Manual (Version 1.07, 06/2016) ------------- 70
Modbus Output Register:
There are two fields on Modbus output register, one is TX CAN message
field and the other is Configuration command field. The addresses of these
fields are described below.
Table5-5: Modbus output register address
Protocol Address
(Base 0)
PLC Address
(Base 1)
Description
Decimal rule
00000 ~ 00006
40001 ~ 40007
TX CAN Message
00256 ~ 00511
40257 ~ 40512
Configuration command
(1) TX CAN Message Field:
The
“TX CAN Message” in the Modbus Output Register is used to stored a
CAN message which will be transmitted to the CAN network.
The TX CAN Message formats are described below:
Word
number
Description
1
Bit 6~15: Reserved
Bit 5: CAN Specification, 0
CAN 2.0A, 1
CAN 2.0B
Bit 4: RTR, 0
No, 1
Yes
Bit 0~3: Data length, value = 0~8
2
Most significant two bytes of CAN Identifier. (Big
endian)
3
Least significant two bytes of CAN Identifier. (Big
endian)
4
The data 1 and data 2 of CAN data field.
5
The data 3 and data 4 of CAN data field.
6
The data 5 and data 6 of CAN data field.
7
The data 7 and data 8 of CAN data field.
