I need help getting a Quatech RS-422 synchronous serial card to work with LabVIEW.

[SetonHall10]

I either need to find a driver to comply or figure out how to get LabVIEW to interface with the PCMCIA card. Or I need to find a place that I can buy an RS-422 Synchronous card that have LabVIEW drivers. Help with either one of these solutions would be appriciated.

[Chris_Rake]

Can you please describe the synchronous needs? Is the data frame the same as async (start, data, parity, stop)?

[SetonHall10]

I work as a summer intern and don't have that much knowledge in the area of serial communication. I was that currently we only need start, data, parity, stop but later on it will need to handle synchronous and HDLC.

[Ben]

Hi SetonHall10,

RS-422 speaks only of the physical layer (electrical characteristics) of the interface.

HDLC is a robust protocol that uses bit stuffing (a special data manipulation technique that ensures the pre-amble pattern used to syncronize the recievers clock with the transmitter).

If your baud rates are low enough, the bits stuffing can be done explicitly using LV. At higher baud rates you will need an interface that can handle the bit stuffing in the hardware.

Check with Quatech for a driver that supports HDLC.

Ohterwise, you maybe be better off purchasing a interface that that comes with a driver.

I have written HDLC and SDLC applications in LV. I have another one coming up in the near future. If you think we can help further, please post
follow-up Q's.

If you find a good suolution, please share.

Ben