mirror of
https://github.com/thiagoralves/OpenPLC_v3.git
synced 2026-08-18 19:48:42 +08:00
54 lines
1.7 KiB
Plaintext
54 lines
1.7 KiB
Plaintext
=============================================
|
|
Migration notes from the 2.0 series (for 3.0)
|
|
=============================================
|
|
|
|
The 3.0 release use a brand new API and this document covers only the general
|
|
changes:
|
|
|
|
- the structure modbus_param_t is gone and is replaced by a new opaque and
|
|
dynamically allocated structure modbus_t.
|
|
|
|
- the slave argument is no more an argument of the Modbus functions, you need to
|
|
call modbus_set_slave first.
|
|
|
|
- the public header file is smaller so some internal defines aren't accessible
|
|
anymore.
|
|
|
|
- all function and constants are respectively prefixed by modbus_ or MODBUS_.
|
|
|
|
- the POSIX error conventions are used (if an error occured, -1 or NULL is
|
|
returned and errno is set accordingly).
|
|
|
|
- coil status and discretes inputs are just bits and force/preset actions have
|
|
been renamed to write actions.
|
|
|
|
We hope you'll enjoy the new API to accept the migration burden!
|
|
|
|
=============================================
|
|
Migration notes from the 1.2 series (for 2.0)
|
|
=============================================
|
|
|
|
Init
|
|
====
|
|
|
|
modbus_init_tcp requires a third new argument, the port number.
|
|
|
|
modbus_init_tcp(modbus_param_t *mb_param, char *ip_address, int port)
|
|
|
|
Set the port to MODBUS_TCP_DEFAULT_PORT to use the default one
|
|
(502). It's convenient to use a port number greater than or equal to
|
|
1024 because it's not necessary to be root to use this port number.
|
|
|
|
|
|
Pointers of data
|
|
================
|
|
|
|
The coil and input status are now stored in an array of type uint8_t
|
|
(in 1.2.X series, array of type int was used). So now, you need to
|
|
pass a pointer of type uint8_t to use read_coil_status(), for example.
|
|
|
|
The holding and input registers are now stored in an array of type
|
|
uint16_t.
|
|
|
|
These changes reduce the memory consumption.
|