MODBUS at F28335

Bruno Luiz Silva

I have to put MODBUS at one F28335. For that I am porting Freemodbus to it, but I'm having problems with the xMBRTUReceiveFSM() function. For some reason, the assert( eSndState == STATE_TX_IDLE ) line is aways activated and break the program.

I tried to find where the eSndState is changed to another state, but I couldn't find. Maybe is some serial configuration, but I couldn't find any error too. Someone has had the same problem? How did you fix? There is some MODBUS code for F28335?

If someone wants to see the actual code to help me: https://github.com/brunoluiz/2833xFreeModbus

PS.: I am not using FIFO at the code

over 12 years ago

0 Maria Todorova over 12 years ago

Guru 13185 points

Hello Bruno,

Did you find the solution?

I think the eSndState should be initialized as STATE_TX_IDLE in this Modbus RTU (mbrtu.c) if your Modbus is Slave (not Master).

Modbus Slave will not send/transmit anything before receiving data from Modbus Master so in this case, xMBRTUTransmitFSM() will never enter STATE_TX_XMIT case which set eSndState = STATE_TX_IDLE so eSndState will never be STATE_TX_IDLE.

Hope this is the case.

Btw, I could not open your CCS project to my CCSv5 using Import Existing CSS Eclipse Project. I am very new on CCS, could you advice me how to open your freeModbus in CCS? Thanks!

0 Abhijit Kelkar over 10 years ago

Intellectual 855 points

Hi. Bruno,

have you compete the F28335 MODBUS using free modbus stack?

I am in same boat so want to know few things.

regards

Abhijit Kelkar

0 Bruno Luiz Silva over 10 years ago in reply to Abhijit Kelkar

Prodigy 145 points

I created my own Modbus library and published it at github: https://github.com/brnluiz (check the 28335ModbusSlave and 28335ModbusMaster)

0 Gautam Iyer over 10 years ago in reply to Bruno Luiz Silva

Guru 192875 points

Great Bruno!
Thanks for sharing :)

Goodluck & Regards,
Gautam

0 Abhijit Kelkar over 10 years ago in reply to Bruno Luiz Silva

Intellectual 855 points

Thanks Bruno, for sharing, I will go th' it & see if it is useful to me.

regards

Abhijit Kelkar

0 Harish Singh over 8 years ago in reply to Bruno Luiz Silva

Intellectual 995 points

Hi there,

The link is not working at all. Please share a working link.

Thanks & Regards,

Harish

0 Brett Larimore over 8 years ago in reply to Harish Singh

TI__Guru 57255 points

Hi Harish,

Please see Bruno's main post for this.
https://e2e.ti.com/support/microcontrollers/c2000/f/171/t/380010

In his github home repo, he also has a MODBUS master implementation.

Thank you,
Brett

0 Bruno Luiz Silva over 8 years ago in reply to Harish Singh

Prodigy 145 points

I changed my handle on GitHub. Thanks for notifying: github.com/.../2833xFreeModbus

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MODBUS at F28335