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luizcantoni / mudbus

Automatically exported from code.google.com/p/mudbus
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mubbus.cpp bugfix #5

Open GoogleCodeExporter opened 9 years ago

GoogleCodeExporter commented 9 years ago 
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 dunners...@gmail.com on 6 Apr 2015 at 4:34

GoogleCodeExporter commented 9 years ago 
also line 136 should be ByteArray[5] = 6;

Original comment by dunners...@gmail.com on 6 Apr 2015 at 4:38

kasperv79 commented 4 years ago

are these corrections verified?

vhu474 commented 11 months ago

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 commented 11 months ago

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