Examples of Modbus/TCP to CAN converter_GCAN

5. Examples
Users can send the Modbus instruction through the network debugging software in the CD. Please choose the TCP Client mode and the remote host address is 192.168.1.10:502 (IP address for the factory settings, can be modified; port number can not be modified).

Please note: check the " 十六进制显示" and " 十六进制发送" when using the software Network Debugging Assistant.

5.1 Read the received CAN frame

For example:

Modbus slave address: 1

Modbus register first address: 0x01 (factory setting)

Function code: 03

Frame format: standard frame

Frame ID: 0x181

CAN frame data: 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08

Modbus master sends request frame:
00 00 00 00 00 06 01 03 00 01 00 04

Response frame of GCAN-205:
00 00 00 00 00 0B 01 03 08 02 01 04 03 06 05 08 07

At this point, the GCAN-205 converter receives a data frame with CAN ID of 0x181.

5.2 Write the CAN frame to be sent

For example：

Modbus slave address: 1

Modbus register first address: 0x101(decimal value is 257, factory setting)

Function code: 16(10H)

Frame format: standard frame

Frame ID: 0x201

CAN frame data: 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08

Modbus master sends request frame:
00 00 00 00 00 0F 01 10 01 01 00 04 08 02 01 04 03 06 05 08 07

Response frame of GCAN-205:
00 00 00 00 00 06 01 10 01 01 00 04

At this point, the CAN terminal of other converters receive a data frame with a CAN ID of 0x201 from the Modbus side.