SW-DK-TM4C129X: Modbus TCP/IP on TM4C129X

Gerhard Reiner

Part Number: SW-DK-TM4C129X

Hi TI-team,

I would like to use the lwIP TCP/IP stack to implement a Modbus TCP/IP protocol on a TM4C129X or MSP432 microcontroller.

I have a DK-TM4C129X development board and went through some examples like the "Ethernet with lwIP" to evaluate the lwIP stack.

Is it possible to take this example as a starting point and modify it for Modbus TCP/IP data transfer or is there a smarter way to start the development?

E.g. is there a ready-to-use library or application to implement Modbus TCP/IP on any TI development board?

Thanks in advance for your support.

Regards, Gerhard

over 1 year ago

0 Charles Tsai over 1 year ago

TI__Guru**** 166726 points

Hi Gerhard,

Gerhard Reiner said:
E.g. is there a ready-to-use library or application to implement Modbus TCP/IP on any TI development board?

No, we do not have any ready to use library or examples for Modbus TCP/IP based on lwip for TM4C129. However, I find this app note for an older generation Stellaris MCU with software collateral that you can take a look. You will be on your own to port this over to Tiva device.

You might find this post useful.

https://e2e.ti.com/support/microcontrollers/arm-based-microcontrollers-group/arm-based-microcontrollers/f/arm-based-microcontrollers-forum/880100/tm4c1294ncpdt-errors-using-lwip-with-freertos/3261592#3261592

0 Gerhard Reiner over 1 year ago in reply to Charles Tsai

Prodigy 10 points

Hi Charles,

thanks a lot for your advice. In fact I found a project called "enet_modbus" which seems to perfectly serve my needs. With the PC based GPL software QModBus I was able to send modbus TCP commands to my application and and also to locate the received data in the buffer of my TivaC controller. Right now I am struggling with the lwIP software to find out, how to form a TCP telegram and send it back to the PC as a modbus response. So far I could not find out how lwIP sends data. Anyway, thanks again for your help.

Regards, Gerhard

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SW-DK-TM4C129X: Modbus TCP/IP on TM4C129X