For NI-6534 PCI, does the internal clock send one 8-bit word, for one port, at the clock's Hi to Lo transition​, Lo-hi, any at transition at all or neither?

Question

here is my understanding of how the internal clock works. There is an 8-bit word for a port ready and waiting. Clock goes at transition, that word id read out, a new word comes up next. Clock transitions again, new word goes out. Is this correct?
Is "clock transition"="update" in manuel, example code language.
What does 8-bit word get sent out on, Hi to Lo, Lo to Hi, either, neither.
No handshake, no trigger.
I am still using "Buffered Pattern Output VI", and am trying to figure out 8-bit word is sent out to the port via the internal clock and how these work together to accomplish this.
Thanks much for help

Answer 1

Nate,
when doing pattern I/O on NI 6534, by default the data is transferred on the falling edge of the internal clock. Therefore, your 8-bit word from the specified (8-bit) port will be transferred at the internal clock's Hi-to-Lo transition. However, you can choose the edge (falling or rising) you want the data transfer to occur at. In labview, you will have to use Digital Mode Config.vi that is called by the DIO Config VI and specify the REQ polarity.
You can look at page 2-18 of the NI 6534 user manual available at the following link for more info.
http://www.ni.com/pdf/manuals/321464c.pdf
-Afreen Siddiqi
www.ni.com/ask