============================= Migration from the 2.0 series ============================= modbus_init_listen_tcp() has been renamed to modbus_slave_listen_tcp() and requires a new argument, the maximal number of connections: int modbus_slave_init_tcp(modbus_param_t *mb_param, int nb_connection); New function modbus_slave_accept_tcp() to etablish a new connection (previously in modbus_init_listen_tcp()): int modbus_slave_accept_tcp(modbus_param_t *mb_param, int *socket); modbus_listen() has been renamed to modbus_slave_receive() and requires a new argument, the socket file descriptor to listen on. If the sockfd is -1, the internal fd of modbus_param_t is used: int modbus_slave_receive(modbus_param_t *mb_param, int sockfd, uint8_t *query, int *query_length); =================================== Migration notes from the 1.2 series =================================== 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. New functions ============= report_slave_id modbus_set_error_handling modbus_mapping_new modbus_mapping_free modbus_init_listen_tcp modbus_listen modbus_manage_query get_slave_query_tcp set_bits_from_byte set_bits_from_bytes get_byte_from_bits Read modbus.h for more informations.