posted Oct 20, 2014, 6:18 AM by Javad Taghia   [ updated Oct 20, 2014, 6:18 AM ]

Modbus Compatibility Classes

To get a really high score when it comes to compatibility with different devices, you want lots of functionality, but minimal code—especially if RAM is limited.

Because the source for this project is open, I imagine it will get many bug-reports and fixes at low cost, and add stability as it ages.

Function CodeMeaning
Class 0: the bare minumum
03 hexRead Multiple Registers
10 hexWrite Multiple Registers
Class 1: ideal
01 hexRead Coils
02 hexRead Inputs
04 hexRead Input Registers
05 hexWrite Coil
06 hexWrite Single Register
07 hexRead Exception Status
Class 2: almost overkill
0F hexForce Multiple Coils
16 hexMask-write Register
17 hexRead,Write Multiple registers

Javad Taghia,
Oct 20, 2014, 6:18 AM
Javad Taghia,
Oct 20, 2014, 6:18 AM