# modbus_set_socket(3) Manual Page

## NAME

modbus_set_socket - set socket of the context

## SYNOPSIS

void modbus_set_socket(modbus_t *ctx, int socket);

## DESCRIPTION

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

There is no return values.

## EXAMPLE

    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);
        }
    }

## SEE ALSO

modbus_get_socket(3)

## AUTHORS

The libmodbus documentation was written by Stéphane Raimbault <stephane.raimbault@gmail.com>