PCI 6254 - Can we do DIO Read/ Write using Port 1 & Port 2?

[rkpat]

Hi,
I'm currently using NI-DAQ-6254 board. As i understand, it has 3 ports:
Port 0 (P0.<0..31>)
Port 1 (PFI.<0..15>)
Port 2 (PFI.<0..15>)

I'm able to use the Port 0 for Digital Read and write, but am not able to do the
same with Port 1 & Port 2.

According to he 6254 Spec, Port 1 & 2 can be used for Static Digital I/P and O/P.
Then, why am i not able to read digital data using Port 1/ Port 2??

I was trying to use an external clock as there is no onboard clock engine on this
board.

Thanks,
rkpat

[JaredA]

Hello,

You can use all 3 ports to perform static Digital I/O. If you program involves any type of sample clock, then you are no longer performing static DIO, but correlated DIO.

You should consider opening a static DIO example and configuring it to read/write from all of the ports. This should work fine for you since there is no clock invovled.

Jared A

[rkpat]

Hi Jared,
thanks for the reply.

just need another clarification...
Am i right in assuming that we cannot do CORRELATED DIO using port 1 & 2??

also, what is the difference between STATIC DIO & CORRELATED DIO?

i will be using an EXTERNAL CLOCK for digital output and input. in this case,
can i still use Port 1/2?

thanks,
Ravi

[JaredA]

Hello,

Correlated DIO enables digital and analog functions to be synchronized with hardware-timed precision. Basically, a clock is associated with the digital functionality.

Static DIO is basic digital IO that employs no handshaking or hardware-controlled timing. There is no clock associated with the functionality.

You are correct in that Port 0 of your M Series is the only DIO port available for correlated DIO. And unfortunately, the use of an external clock for ports 1 and 2 is not possible with the M Series. Only port 0 can utilize a hardware clock.

I hope this helps.

Jared A