Disconnect All Except a Single Relay

[D_A_N_A_S]

Hi,

We have a test system which uses NI PXI 2570 (40 Channel SPDT). We control some data and lines including the DUT ON/OFF with these relays. Before running each test case, I would like to have a resetting of relays (using Disconnect all) except the relay where I connected the DUT ON/OFF. Could anyone suggest a best method for this?

Thanks in advance,

Sanad MM

[chericks1]

Hi Sanad MM,

I'm assuming you cannot allow the DUT ON/OFF relay to toggle.  Otherwise, simply call Disconnect All and then connect the DUT ON/OFF relay.

I'm also assuming you are attempting to avoid the iterative method of obtaining each relay position one at a time and toggling those that are not reset or DUT ON/OFF.

Are you using or have you looked into NI Switch Executive?  As of NI Switch Executive version 2.1.1 and later, niSE Connect And Disconnect allows you to disconnect all previous connections by setting the Disconnection Specification string equal to * (or asterisk).  The Connection Specification string corresponding to the DUT ON/OFF relay would allow it to remain closed while all the other relays are reset.  I've attached an example and the picture of the block diagram (in case other readers do not have LabVIEW or Switch Executive installed).

Hope this helps!

Chad Erickson
Switch Product Support Engineer
NI - USA

[D_A_N_A_S]

Hi Chad Erickson,

We are using NI Switch Executive Version 2.1.1. I have tried with “connect and disconnect” option. Now I have one question.  We are using PXI 2570 (40 Channel SPDT). I have attached the code which I am using. When I disconnect NO-COM connection, it is not physically disconnecting the connections. If we want to physically disconnect we have to switch to NC-COM (as in picture). Is this one the expected behavior?

Thanks,

Sanad MM

[chericks1]

Hi Sanad MM,

As you note, the command to disconnect NO-COM does not physically connect NC-COM.  This is expected behavior. 

Disconnect does not activate the relay until the ensuing Connect is executed.  Disconnecting NO-COM informs the software so that connecting to NC-COM can occur without error.  

Hope this helps!

Chad Erickson
Switch Product Support Engineer
NI - USA

[chericks1]

Addendum: This is the correct behavior for SPDT switch modules.  These switch modules include the PXI-2548, PXI-2549, PXI-2558, PXI-2559, PXI-2566, PXI-2570, PXI-2598, and PXI-2599, as well as the SCXI-1160, SCXI-1161, and SCXI-1166.

Chad Erickson
Switch Product Support Engineer
NI - USA