Peter M. Groen / libmodbus

Useful functions when you are confronted with equipment which does
not respect the protocol, which behaves strangely or when you wish
to move away from the standard.

Thank you @mhei for the great initial version.

When compiling with gcc and option -Wconversion it fixes the
warning message

  warning: conversion from ‘X’ {aka ‘x’} to ‘Y’ {aka ‘y’} may change value

Signed-off-by: José Bollo <jose.bollo@iot.bzh>

In case resulting value should be negative it is incorrect to use '+' operator to construct it from pieces, because highest bytes will result in negative number after bitwise shift while others will stay positive. Replacing addition with '|' should solve the issue.

Since SPDX release 3.0 LGPL-2.1+ became LGPL-2.1-or-later. Hence
replace the deprecated identifiers.

Closes #461

Related to 52ab1bbea760ed8eaca184f7d875a2f52a116d0f.
The arguments have been changed (see documentation).

https://groups.google.com/d/msg/libmodbus/aXO8nBzW4Ew/uVGTDmvvBAAJ

This allows to place the coils/registers at any virtual
start address, not only at address 0. This can be useful e.g.
when the server has to fulfill a specification in which
registers are expected at predefined locations.

Signed-off-by: Michael Heimpold <mhei@heimpold.de>

Signed-off-by: Michael Heimpold <mhei@heimpold.de>

This replaces the lengthy license text headers with a short
and standardized license tag. See http://spdx.org for details.

This is useful e.g. for license compliance tools which scan
through files and generate a report of the licenses used
in a project.

Signed-off-by: Michael Heimpold <mhei@heimpold.de>

Function modbus_receive_from has no implementation in the library and is not used anywhere.

Change API of function for libmodbus v3.2.0

- add byte timeout tests (TCP backend only)
- update and improve documentation
- long timeout values are now uint32_t so it changes the API
  to disable byte timeout

https://www.securecoding.cert.org/confluence/display/seccode/DCL37-C.+Do+not+declare+or+define+a+reserved+identifier
Not applied to libmodbus constants for now...

- update documentation
- 5 new tests
- updated NEWS file
- avoid include of time.h

The index variable shadowed a variable in the standard library causing
warnings. Renaming the 'index' variable to 'idx' resolves the issue.

It's strongly recommended to update your libmodbus library if you
use it in a slave/server application in a not trusted environment.

Debian package of libmodbus 3.0.4 already contains a patch to
mitigate the exploit but the patch isn't as strong than this one.

This regression comes from Visual Studio patches.

- change return argument from void to int
- update documentation

Thanks Tobias Doerffel.

Fix EXXX values defined in Microsoft C Runtime 10

Add macros in libmodbus.txt and:
- modbus_get_byte_from_bits.txt
- modbus_get_float.txt
- modbus_reply.txt
- modbus_reply_exception.txt
- modbus_set_bits_from_byte.txt
- modbus_set_bits_from_bytes.txt
- modbus_set_float.txt

The function name was confusing because the write operation is performed
before the read. Take care to swap the arguments in the migration process.