modbus_get_byte_timeout - get timeout between bytes
int modbus_get_byte_timeout(modbus_t *ctx, uint32_t *to_sec, uint32_t *to_usec);The modbus_get_byte_timeout() function shall store the timeout interval
between two consecutive bytes of the same message in the to_sec and to_usec
arguments.
The function shall return 0 if successful. Otherwise it shall return -1 and set errno.
uint32_t to_sec;
uint32_t to_usec;
/* Save original timeout */
modbus_get_byte_timeout(ctx, &to_sec, &to_usec);