can digital I/O lines emulate a parallel port?

[z crittendon]

BACKGROUND:
I am writing a VI that needs to sample multiple analog channels at high speeds (~2 msec) while simultaneously receiving byte-sized codes transmitted from a second computer (from either it's serial port or parallel port). These other posts of mine might help you get a better idea of what I'm doing:

http://exchange.ni.com/servlet/Redirect?id=1052290
http://exchange.ni.com/servlet/Redirect?id=1057299

THE PROBLEM:
I need a way to receive these codes at the same high sample rate that the analog channels are being sampled with, and they need to be on the same timing signal (so I know when the codes arrived relative to the analog data). Thus I can't use the built in serial or parallel ports, since the timing would
be inaccurate at such high speeds.

MY QUESTION:
Is there an established way to make the digital I/O lines on a NI daq board receive codes from a serial or parallel port? I am using a PCI-6033e, so if I can just use the digital I/O lines on that board, that would be ideal. However, I would also be willing to buy a sepparate digital I/O board that could be linked (for timing purposes) via an RTSI bus, and use that to receive the bytes from the second computer.

Any ideas for a software or hardware solution to this problem?

Thanks,
Zach Crittendon

[Filipe A.]

Zach;

The problem on using the 6033 board on that task is that board doesn't have handshaking lines. So, you will need to make function calls to update the values of the digital lines. That is not pratical when high speed is needed. One thing you can do is to have one of the handshaking digital boards at the host computer (sending the digital words) and another one at the client computer (reading those digital words) synchronized with the 6033 via RTSI. With that configuration one can assure high accuracy and good synchronization at high speeds.
Hope this helps.
Filipe
Applications Engineer
National Instruments

[z crittendon]

Thanks, Filipe. That's pretty much what I expected as far as the PCI-6033 card was concerned.

However, one thing I failed to mention was that the host computer can only use its standard built-in serial or parallel port, not an NI DIO card (the signals are coming from antequated software that can't realistically be ported to use an NI card).

So...is there a way to take a parallel-port signal from the host computer and have an NI DIO card on the client computer receive it? (Presumably after passing through some sort of adapter, if necessary.) If so, what sort of DIO card should I look at?

Thanks again,
Zach Crittendon