Home Contents | # Control signals | Rawio | Core4 Lua Event System

## SYNOPSIS

1. flag = handle:rawio:rts()
2. flag = handle:rawio:cts()
3. flag = handle:rawio:dtr()
4. flag = handle:rawio:dsr()
5. flag = handle:rawio:dcd()
6. flag = handle:rawio:rng()

## DESCRIPTION

This is a set of functions to retrieve the current state of the serial port control signals RTS, CTS, DTR, DSR, DCD, and RNG (Ring).

## RETURN VALUE

On success, returns a boolean indicating the state of the control signal. On failure, returns nil.

## ERRORS

Fails if the handle is not a serial port (TTY device).

## NOTES

It depends on the underlying hardware which control signals are actually available. On normal RS232 ports, often only RTS/CTS is available. On RS485 ports, there are no control signals.

## SEE ALSO

rawio:break, rawio:device, rawio:drain, rawio:fd, rawio:flush, rawio:name, rawio:rxcnt, rawio:setDtr, rawio:setRts, rawio:setupComm, rawio:start, rawio:stop, rawio:txcnt