Routing counter to PFI line/ not routing counter to any external port - How is it done?

[Yopp Qax]

Hi!

I am using a counter to create a sample clock for digital output. The counter looks just like the one in the example attached.
I now discovered that the counter frequency is routed to PFI12 of my NI6259. I don´t know why, I haven´t done this. I don´t want the counter at any external line because it causes interferences.
If it is not possible to route the counter to no port, how can I route it to another port? I did not find any answer in the knowledge base to that question.

Thanks for your help.

Best regards,
Yopp

[Vsh]

Hi,

The default pin for Counter 0 in PCI 6259 is pin no. 2 and it is also PFI 12. Similarly for Counter 1 is PFI 13 ( pin no. 40). So if u are generating in a counter, I believe that will be reflected in the output pin.

About routing, you can refer to MAX for available routing possibilites for all the signals(in the device routes tab). You can use "DAQmx Connect Terminals.vi" for signal routing. Unfortunately you cannot rout your signal to any digial lines. You can rout it to PFI terminals which also share the Digital lines. In PCI 6259, port 2 and 3 are shared with PFIs.

 Let say u have routed your counter signal to PFI 5 then you should be able to get the signal out from Digital line P1.5.

Best Regards

[JB]

Have a look at the DAQmx routing functions : Functions palette >> Measurement I/O >> DAQmx - Data Acquisition >> DAQmx Advanced >> DAQmx Signal Routing
It should at least be possible to route the signal to another PFI line.

[JB]

If have just tried to insert a DAQmx Channel property node to set the counter output terminal to an empty constant. I can't run the example because I don't have the hardware but at least there is no error in the error cluster.




Message Edité par JB le 02-27-2008 05:10 PM

[Yopp Qax]

Thanks for the replies!

I tried the signal routing, but it doesn´t work as I expected. I routed PFI12 to PFI 15. Now the signal is at both outputs. Even if the deactivate or delete the signal routing VI it stays that way.
If there is a possibility to route it and get rid of it at PFI2, I would choose one of the PXI trigger lines, as the are not in the screw terminal

I attached the signal routing example I made, could you have a look at it, maybe I did it wrong?

[Yopp Qax]

@JB: That doesn´t work. I get error -200971. Seems that an empty channel property is not allowed, but it was a good idea!!!

Regards, Yopp

[tbob]

If your original problem is that the signal at the PFI lines is causing interference, have you tried terminating the PFI lines in question with a resistor?  This may solve the interference problem.  Try anywhere from 50 ohm to 10K.  Tie the resistor directly on the terminal block from PFI to ground.

[JB]

I didn't get this error ! (Probe 1 in above picture). But like mentionned before I could not run the whole application.

[Vsh]

If it is just to get rid of only PFI 12, then may be use of Counter 1 out (PFI 13) doesn't help?

Else using an AO clock or AI clock would be a better Idea to generate the digital waveform. You just have to start a dummy AI or AO operation and rout its clock to your DO sample clock.!

[Yopp Qax]

Thanks for all your help! @JB: The error occurs when running the application. @tbob: This would be the last option. But why am I buying a pricy measurement system, when have to do such silly things? @VSH: I am using SCC68 terminal which has a field which holes (don´t what it is called in english;)), where one can build additional circuits. So did I. Unfortunatly the field is next to most of the PFI lines, so I would route the unwanted signal to the PFI line that is farest away from my built circuit. AO or AI clock is not an option, because the clock has to be 4MHz. I had big problems to discover this solution to get a 4MHz clock and it seems to be the only one. Regards, Yopp