I am trying to write an application that will allow me to continuosly scan PORTA, PORTB and PORTC (8255 Chip). How do I go about doing this? I would like to use VB6. I have tried the examples, but they keep giving me errors, indicating that the DAC 6025E may not support continous data acq. operations. In any given case no continous DAQ operation seems to work with the VB controls. The card tests out fine using the NI Measurement @ Automation sofware.
The 8255 chip is a static (unstrobed) digital I/O chip. Therefore, none of the buffered or pattern NI-DAQ functions or ComponentWorks controls will work a 8255-based device such as the 6025E. The errors you are getting are likely, "the device does not support the requested action" type errors. In software, you will be able to do is immediate i/o - that is read or write ports immediately with a software command.
For continuous buffered digital I/O, I would suggest looking into the 6533 or 6534 family of digital I/O devices.