Manual Manipulation of Serial Communication Handshake Lines

Serial port 2 bits in and 2 bits out.
(using manual Manipulation of Serial Communication Handshake Lines and SerialStatus function).

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2 Bits Out

This ActiveX control can be used to manually manipulate the hardware handshaking lines of a serial communications port. To do this, follow the following steps.

Set the state of the control line before the port is opened.
Open the port.
Then assert the control line to the state you wish.

Example:

'Set output

IO1.SerialRTSControl(1) 'or 0 see SerialRTSControl documentation at main web page "Functions"

IO1.SerialDTRControl(0)

IO1.Open("COM2:", "baud=9600 parity=N data=8 stop=1")

IO1.SerialRTSControl(5) 'or 6 to change RTS state as desired.

IO1.SerialDTRControl(5)

2 Bits In

Example:

'Read input

Result = IO1.SerialStatus

If (Result And SERIAL_CTS_ON) Then

Check1.Value = 1

Else

Check1.Value = 0

End If

If (Result And SERIAL_DSR_ON) Then

Check2.Value = 1

Else

Check2.Value = 0

End If

Note1:SERIAL_CTS_ON and SERIAL_DSR_ON need to be defined somewhere and set to the correct values. See "Functions" and SerialStatus() for more information.

Note2: The voltages at the serial port are + and - (12 to 15 v typical). Sometimes you can get away with 0 to 5 volts for an input but it is not guaranteed.

See: Serial and parallel cable schematics and wiring diagrams.