
I-7530A-MR-FD Modbus RTU to CAN
Converter User’s Manual (Version 1.0, 08/2022) ------------- 74
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(1): Modbus output register address
(
general CAN)
Protocol Address
(Base 0)
PLC Address
(4x Base 1)
Description
Decimal rule
00000 ~ 00006
00001 ~ 00007
TX CAN Message
00256 ~ 00511
00257 ~ 00512
Configuration command
Table5-5(2): Modbus output register address
(CAN FD)
Protocol Address
(Base 0)
PLC Address
(4x Base 1)
Description
Decimal rule
00000 ~ 00034
00001 ~ 00035
TX CAN Message
00256 ~ 00511
00257 ~ 00512
Configuration command
(1) TX CAN Message Field:
The
“TX CAN Message” in the Modbus Output Register is used to store a
CAN message which will be transmitted to the CAN network.
The TX CAN Message formats are described below:
general CAN:
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.