28335ModbusSlave

MODBUS implementation for F28335 DSP. This was developed by Bruno Luiz (@brunoluiz) to a project for TRACTEBEL in partnership with CERTI Foundation.

Installing

Structure

All modbus implementation are at contrib/modbus folder. We suggest you to put all your code at source folder.

If you need any DSP2833x header file you can find it at contrib/DSP2833x

Include paths

If you use Code Composer 4 (or later), import the C/C++ Project Settings from ccs_configs/28335ModbusCSettings.xml file.

Another way to include the right paths is changing the "Include Options". At CCS 6.x you have to go to Project Settings (ALT+ENTER), then Build C200 Compiler Include Options. You've to include the following paths:

• contrib/modbus/include
• contrib/modbus/plataform/ DSP2833x/include
• contrib/DSP2833x/DSP2833x_common/include
• contrib/DSP2833x/DSP2833x_headers/include

If your project uses custom DSP2833x headers/files you don't need the two last paths.

Don't forget to exclude from compilation the contrib/dspProfiling and contrib/DSP2833x (right mouse click ``` Exclude from Build).

Implementing

Normally this code will be implemented at main.c

1. Include the ModbusSlave.h header
2. Change the configuration files: a. ModbusSettings.h: baudrate, parity, debug modes, buffer size (the max size of a frame)... b. Serial.c & Timer.c: if your CLOCK or LSPCLK are different from 150 e 37500000, change those files
3. Declare the modbus object with ModbusSlave mb;
4. Initialize modbus object with mb = construct_ModbusSlave();
5. At some loop, call modbus object with mb.loopStates(&mb);

Using memory map

To use the memory map you will need to change the ModbusDataMap.h file with the variables that you want.

Don't forget that coils/inputs have the bit field = 1 (bool VAR:1) and that holding registers are meant to be 32 bits (long or float).

If your variables will not be 32 bits, you will have to change some ModbusDataHandler.c. I commented MODIFIABLE at the functions which needs tweaks (readAnalogData, presetSingleRegister, presetMultipleRegisters).