# modbus_rtu_get_rts_delay ## Name modbus_rtu_get_rts_delay - get the current RTS delay in RTU ## Synopsis ```c int modbus_rtu_get_rts_delay(modbus_t *ctx); ``` ## Description The `modbus_rtu_get_rts_delay()` function shall get the current Request To Send delay period of the libmodbus context 'ctx'. This function can only be used with a context using a RTU backend. ## Return value The function shall return the current RTS delay in microseconds if successful. Otherwise it shall return -1 and set errno to one of the values defined below. ## Errors - *EINVAL*, the libmodbus backend is not RTU. ## See also - [modbus_rtu_set_rts_delay](modbus_rtu_set_rts_delay.md)