PXI-2575 Connections

[JohanBrits]

I would like to use the PXI-2575 in a 1-wire configuration.
Is it possible to connect two of the multiplexer channels, but not to the common channel, using a scan list? Example: Ch0->Ch1.

From the hardware diagram it seems possible, but I do not know if it is a valid connection from a driver point of view.

Thank you.

[_Brian_]

Johan:

The PXI-2575 has only multiplexer topologies.  For multiplexers, the driver follows a rule that you can only connect one channel at a time.  This applies to both the connect channel and scanlist functions of the driver.  So the only way I see your case working is via the relay api; since it does not follow this rule.  Can you use the relay api?  What is the basis for you wanting to use a scanlist?

Brian

[JohanBrits]

Thanks Brian

I can use the relay api, but if I could use a scanlist I would be able to use hardware handshaking on the PXI trigger bus between the switch and the DMM I am using.


Johan

[wildcat_600]

Hello Johan,

There may be another way that you could perform this action by using scanlists.  However this is a roundabout way that would require you switch to be used in a different configuration.  I don't know exactly what connections you need to make with your switch so I'm not sure if this will work for you, but I will suggest it anyway as a possible option.

The PXI-2527 has 2 multiplexers on board that can be controlled separately.  The two configurations that allow you to use both multiplexers separately are the "1-Wire Dual 32x1 Mux" and "2-Wire Dual 16x1 Mux".  If you were to use the 1-Wire mode and make a few hardwires on your terminal block you can do things such as connecting ch0 to ch1, ch0 to ch5, ch11 to ch13, etc.  I have attached a picture that shows what hardwires you would need to make.  By performing this workaround you are using the 2nd Mux just for routing signals to the 1st Mux.  First hardwire com0 to com1. Then hardwire all of the channels from the 2nd Mux to the channels on the 1st Mux.  After making these connections you can setup scan lists by using strings such as "ch0->com0 & ch32->com1;" to connect ch0 to ch1.

I know this is a different way of doing things but it is the only option I could think of to still allow you to perform the behavior you want using scanlists with only your one board.  I hope this helps.  Let me know if you have any other questions about what I described.

Have a great day,

Brian P.

Applications Engineer

[wildcat_600]

Johan,

I'm sorry, but forget about my previous post.  What I wrote only works for the PXI-2527 not your PXI-2575!  I was looking at two posts at once and I used the board off another post with your question.  Sorry about that.

Since the 2575 is a single MUX, there really isn't a way to use a scanlist to perform relay operations.  The behavior you describe sounds like you need a Matix configuration instead of a Multiplexer.

Again sorry about the confusion!

Brian P.