Modbus Library does not link

Mbed Studio
1

I cannot get any of the various modbus libraries to build.
I am currently trying with Modbus - Trying to make Modbus code into a lib | Mbed
but have had similar issues with other versions.
It compiles ok but the I get 4 similar errors when it tries to link e.g.
[Error] @0,0: L6218E: Undefined symbol eMBRegCoilsCB(unsigned char*, unsigned short, unsigned short, eMBRegisterMode) (referred from BUILD/LPC1768/ARMC6/Modbus/mbfunccoils.o).
Can anyone help?

2

This is a callback routine that you have to provide in your application Code.

3

Thanks very much for responding. And apologies for my lack of knowledge. Would it be possible to give me a quick example of how to include the callback in my application?

4

There is an example where this lib is used:

5

Thats sorted me. Thanks very much