modbus_set_socket(3)

modbus_set_socket3

Set socket of the context

Usage

int modbus_set_socket(modbus_t *ctx, int s);

Overview

The modbus_set_socket() function shall set the socket or file descriptor in the libmodbus context. This function is useful for managing multiple client connections to the same server.

Return value

The function shall return 0 if successful. Otherwise it shall return -1 and set errno.

Examples

ctx = modbus_new_tcp("127.0.0.1", 1502);
server_socket = modbus_tcp_listen(ctx, NB_CONNECTION);
FD_ZERO(&rdset);
FD_SET(server_socket, &rdset);
/* .... */
if (FD_ISSET(master_socket, &rdset)) {
    modbus_set_socket(ctx, master_socket);
    rc = modbus_receive(ctx, query);
    if (rc != -1) {
        modbus_reply(ctx, query, rc, mb_mapping);
    }
}

Releases

6 releases since Debian 7 (Wheezy); the text changed 5 times.

  1. 7
  2. 8
  3. 9
  4. 10
  5. 11
  6. 12

Authors

The libmodbus documentation was written by Stéphane Raimbault <[email protected]>

From libmodbus-dev 3.1.6-2.1 in Debian 12 (Bookworm). Parsed by carta from the page's man source.