mubbus.cpp bugfix

[GoogleCodeExporter]

I noticed an error in your library. Line 137 should be MessageLength = 12;
I was getting an error when writing to coils as the response was incorrect.

Original issue reported on code.google.com by [email protected] on 6 Apr 2015 at 4:34

[kasperv79]

are these corrections verified?

[vhu474]

YES. Confirmed and verified to fix the issue on my Weintek HMI screen Modbus. Please merge this into main branch.
ByteArray[4 to 5] corresponds to message length + 1 in bytes. On main, its 2, which is clearly wrong. The modbus message itself is 5 bytes

MessageLength is 8 on main, which i dont know how they got. The Modbus TCP/IP ADU header itself is 8 bytes, not even including the modbus message. This should be 12.

Source: https://www.prosoft-technology.com/kb/assets/intro_modbustcp.pdf

[vhu474]

Also, this is the official repo that Controllino uses for their HMIs. I hope this issue gets fixed.