Improve compatibility of next release v3.2 on modbus_mapping_t

[stephane]

libmodbus version

Migration from v3.0.6 to libmodbus v3.2.

Description

Migration would be easier if the new offset (now start) fields would be appended to end of the structure https://github.com/stephane/libmodbus/blob/master/src/modbus.h#L159

https://groups.google.com/d/msg/libmodbus/rEIbtPt8FZI/O3hzAd0LCQAJ

[KalaiK7]

hi i need a sample how to communicate to muliple salve connected to the same Modbus,
How we know which slave id id ampped to which sensor,am struggles a lot in mulitiple slave communication and changing the slave id , i can able to read by default slave id(i.e., 1), suppose if i change the slave id to 2 i cant read.

i would like to know what are the basis steps to be followed to change the slave id, and to read the value .am new to mod bus implementation can u guid eme how to rectify the issue , If any basic sample available in c program can u share plz