NAME

       modbus_receive_confirmation - receive a confirmation request

SYNOPSIS

       int modbus_receive_confirmation(modbus_t *ctx, uint8_t *rsp);

DESCRIPTION

       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 used to receive request not handled by the library.

       The maximum size of the response depends on the used backend, in RTU the rsp array must be
       MODBUS_RTU_MAX_ADU_LENGTH bytes and in TCP it must be MODBUS_TCP_MAX_ADU_LENGTH bytes. If you want to
       write code compatible with both, you can use the constant MODBUS_MAX_ADU_LENGTH (maximum value of all
       libmodbus backends). Take care to allocate enough memory to store responses to avoid crashes of your
       server.

RETURN VALUE

       The function shall store the confirmation request in rsp and return the response length if sucessful. The
       returned request length can be zero if the indication request is ignored (eg. a query for another slave
       in RTU mode). Otherwise it shall return -1 and set errno.

EXAMPLE

           uint8_t rsp[MODBUS_MAX_ADU_LENGTH];
           rc = modbus_receive_confirmation(ctx, rsp);

SEE ALSO

       modbus_send_raw_request(3)

AUTHORS

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