Using Modbus Rtu Command To Get A Can Message - ICP DAS USA I-7530A-MR-FD User Manual

5.2.1 Using Modbus RTU command to get a CAN Message

When the I-7530A-MR-FD is set to the Modbus Slave mode, each CAN
message (except the CAN message whose CAN IDs are defined in the Specific
CAN Message field) received from the CAN network will be stored into the
"Normal CAN Message" field. Users can use the Modbus RTU command
(function code 04
Message" field (refer to table 5-2.). The start address of each command must
be set to 0000
hex
CAN message uses 9 address space. After reading the registers by the Modbus
command, the content of the registers of the read CAN message is covered by
the unread CAN message which will be read next.
The following examples all take the general CAN message as an example,
and the usage of CAN FD is only different in Start Address &Word Count (Byte
Count).
Example1:
Use Modbus RTU command (function code 04
Figure 5-3: Use the Modbus command to read one CAN message.
I-7530A-MR-FD Modbus RTU to CAN Converter User's Manual (Version 1.0, 08/2022) ------------- 84
) to read the CAN message from the "Normal CAN
hex
and the data length field must be a multiple of 9 because one
) to read one CAN message:
hex