Peter M. Groen / libmodbus

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

Avoid incompatibility with GPLv2 program. This change has been approved by
Tobias Doerffel, Florian octo Forster and Hannu Vuolasaho.

The two modes are complementary, MODBUS_ERROR_RECOVERY_LINK handles
errors at data link level (bad file descriptor, timeout, etc) and
MODBUS_ERROR_RECOVERY_PROTOCOL checks Modbus error (eg. invalid
function code or trame length).

This change introduces the use of the Sleep function for Windows.
Some duplicated code has been moved from backends to modbus core.
A new debug message is now available when a flush occurs.

The unit tests are now based on this error recovery code.

The following functions have been renamed:
- modbus_get_timeout_begin -> modbus_get_response_timeout
- modbus_set_timeout_begin -> modbus_set_response_timeout
- modbus_get_timeout_end -> modbus_get_byte_timeout
- modbus_set_timeout_end -> modbus_set_byte_timeout

The meaning of these timeout intervals is now clearer. The documentation
has been updated.

These new functions seem clearer than the recent modbus_receive_from
function IHMO. This change fixes the bandwidth-server-many-up program.

Split the original modbus_receive function in two functions to avoid
the strange -1 value to ignore the sockfd argument.

The arguments are surrounded by parentheses to be evaluated first.

The _modbus_receive_confirmation()_ function shall receive a
request via the socket of the context 'ctx'. This function must be
used for debugging purposes because the received response isn't
checked against the initial request. This function can be
convenient to receive request not handled by the library.

The _modbus_send_raw_request()_ function shall send a request via
the socket of the context 'ctx'. This function must be used for
debugging purposes because you have to take care to make a valid
request by hand. The function only adds to the message, the header
or CRC of the selected backend, so 'raw_req' must start and contain
at least a slave/unit identifier and a function code. This function
can be used to send request not handled by the library.

Reported by Allan Cornet.

Contributed by Dominic Storey.
- new function modbus_reply_exception
- unit test

- MODBUS_GET_INT32_FROM_INT16
- MODBUS_GET_INT16_FROM_INT8
- MODBUS_SET_INT16_TO_INT8
- check the trame length before indexing in unit-test-server

- new public function
- change unit-test-server.c to be transport layer independant (query
  and header_length)

Reported by Ivan Giuliani <giuliani.v@gmail.com>
It was not possible to use libmodbus outside of projects without
config.h file.

The inclusion has been removed from the public header.

Signed-off-by: Stéphane Raimbault <stephane.raimbault@gmail.com>

These functions have no meaning in RTU so it's better to specialize
the names and remove them from the backend.

- remove the functions from the backend
- update tests to handle RTU mode (master and slave)
- add command line options to tests (rtu or tcp)

- move termios header in RTU backend
- move TCP headers in TCP backend
- use native serial on Win32 for Cygwin
- avoid too many defines

This change fixes a compilation problem in MinGW. As general rule,
each header must be as independent as possible.

Added support for native Win32 based on
https://code.launchpad.net/~thepyper/libmodbus/win32-native
This mainly affects the RTU implementation as the TCP/IP socket
interface is the same thanks to the winsocks library. The interface
for using the serial port is completely different on Win32 and is now
implemented accordingly.

Signed-off-by: Stéphane Raimbault <stephane.raimbault@gmail.com>

All declarations in modbus-rtu.h and modbus-tcp.h should be inside
MODBUS_BEGIN_DECLS and MODBUS_END_DECLS in order to make that functions
properly accessible in C++ files.

Signed-off-by: Stéphane Raimbault <stephane.raimbault@gmail.com>

All private functions and constants are now prefixed by _.
The modbus protocol uses entry points to call specific functions.

If <sys/time.h> is not included before "modbus.h" as struct timeval
is not declared. This behavior was observed while building libmodbus
for QNX.

Signed-off-by: Matthias Weisser <weisserm@arcor.de>

- partial revert of 93ce13656103cbb459ebd630d055a008dbb059f3
- it was a bit confusing to always edit modbus.h.in
- the header inclusion still unchanged (<modbus.h>)

The library is now simpler to include (only one <modbus.h>)
To avoid confusion MB_VERSION defines have been renamed to
LIBMODBUS_VERSION.

This reverts commit df0cf7927249954f15e0aa85b02d21b990fa9af9.
Use <modbus.h> in tests.

This time the change is definitive :)

- the return value is used to pass the message length
- remove the hack on exception check in modbus receive
- update tests

- adjusts various comments on return values
- updated tests
- added entry to MIGRATION

- new function modbus_flush
- new names and values for error defines
- finer recovery on error
- merge TOO_MANY_DATA and INVALID_DATA
- stop unit-test-master at the first error
- FLUSH_OR_RECONNECT_ON_ERROR -> FLUSH_OR_CONNECT_ON_ERROR
- more precise tests in unit-test-master