is there anyway to send and receive data via the same parrallel port

[kevinhy]

I have 3 wire which have been connected to parallel port pin 2, 3 & 4.  pin 2 and 3 are for sending out signal (for example, by sending "1" to the parallel port,  the first wire will be at a high voltage and a certain machine will start running; if "2" is sent to the port, the machine will react in certain way). and I am trying to use pin 4 to receive singal ---- a feedback from the machine to notify the user that the previous action is complete and ready to do the next.  I am using 7.1 "port in" and "port out". If seems that I can't use the port to receive signals, because whatever the feedback is, the number i read from the port is always the same as the last number I sent out 😞 Is what I am trying to do achieveable?  Is there a way (hopefully simple) to do it?

Thanks in advance!

[Conseils]

It could be that you need to configure your parallel port in the BIOS to support Input and Output
You may also need to correctly activate the parallel port lines and select the correct ones for input and output respectively depending on the 'mode' the parallel port is in.

Check here for lots of good data on using parallel ports for I/O

Some warnings though: -
  unlike specialised hardware the status of the parallel port lines during power up will likely be undetermined!!
  Don't forget other programs might just decide to have a go at the parallel port as well.

Good luck