Issue Details

I see that some NI Switch Modules support the Switch Health Center, Resistive Self-Test, and/or Temperature Monitoring. Which modules support these features, and what other features do they support?

Solution

Switch Health Center

Several NI Switch matrix modules released in 2015 and later now have access to the NI Switch Health Center. This was previously available only for NI SwitchBlock. The Switch Health Center allows users to monitor relay health and failure modes. Through software, a user can check if a relay is stuck closed (shorted) or stuck open, and can export this report with relay health and lifetime.



As of September 2017, this feature is supported by the following modules:

• PXIe-2737 - 4x64 2-Wire Matrix
• PXIe-2738 - 8x32 2-Wire Matrix
• PXIe-2739 - 16x16 2-Wire Matrix
• All NI SwitchBlock modules. 

A list of all available SwitchBlock modules can be found below at Matrix Modules for SwitchBlock.


Resistive Self-Test

As a part of the Switch Health Center, the new NI Switch matrix modules also include a Resistive Self-Test. This feature is not supported by SwitchBlock modules, but is currently supported by the following modules:
 

• PXIe-2737 - 4x64 2-Wire Matrix
• PXIe-2738 - 8x32 2-Wire Matrix
• PXIe-2739 - 16x16 2-Wire Matrix

 
When relays approach end-of-life, they will have increasing (or dramatically changing) levels of resistance across their paths. With Resistive Self-Test, users can now monitor the path resistance across each relay without connecting any external measurement devices. Not available on pre-2015 modules, this allows users to predict when relays are reaching end-of-life, and replace relays before they fail.



Highlighted in blue, resistance information includes the minimum and maximum resistance changes observed over a set of measurements, as well as the average difference. These differences are the change in resistance relative to a baseline resistance measured at the time the device was manufactured. 

If the average difference is high, or if there is a large disparity between the minimum and maximum difference, it can indicate that relays are nearing end-of-life. Further information about this feature can be found in the NI Switches Help, installed with NI-SWITCH 15.1 or later.
 
On-Module Temperature Sensors 

The PXIe-2737, PXIe-2738, and PXIe-2739 (and the PXI-2542, PXI-2543, and PXI-2544 modules) include on-module temperature sensors. Temperature readings can be accessed from the NI Switch property node within LabVIEW, as seen below. Because temperature can impact resistance levels and data readings, monitoring temperature allows users to better understand and account for their testing conditions.

Additional Information

Starting in 2015, National Instruments released several NI Switch modules with a variety of new advantages. Some of these include Resistive Self-Test, on-module temperature monitoring, use of the Switch Health Center, and installation independent from DAQmx. NI Switch modules with these features are sometimes referred to as "CA4" devices, where modules released before 1/1/2015 are either CA1, CA2, or CA3.

Installation Separate from DAQmx 

When using only these modules, the NI-SWITCH driver can be installed separately from NI-DAQmx . This is done by selecting the Custom install option during installation and has the advantage of a smaller installation size. 
 

Scanning

The Switch modules released after 1/1/2015 do not include scanning or triggering. This means the new Switch modules will not perform DMM-Switch handshaking functions and cannot be used with scan lists.

 

Simulation

Like older modules, the new Switch modules can be simulated though LabVIEW by using niSwitch Initialize With Options.vi from the NI-SWITCH palette. Note that this simulation will not persist between sessions: when the session is closed, the simulated card will be deleted. In addition, the new simulated modules can not currently be created through MAX.

 

NI Switch Executive

The new Switch modules can be used in Switch Executive but must be added as IVI devices and will not appear automatically when using Switche Executive versions before 15.1. Note that native Switch Executive support was added in Switch Executive version 15.1. Once a topology (found in the NI Switch Help under each device) is added to the IVI session, the device can be programmed using the graphical schematic interface.