Another important step during the development of an automated test system is the initial testing and debugging of signal connections. During this phase, you make simple measurements to prove that instruments are properly connected and functioning and that measurement results are accurate. For this stage, NI offers soft front panels (SFPs) - stand-alone software applications that provide a simple way to monitor and control hardware interactively. Figure 3 shows the NI-SWITCH and NI-DMM soft front panels.
Figure 3. NI-SWITCH (top) and NI-DMM (bottom) Soft Front Panels
As you can see from Figure 3, you can use the NI-DMM SFP to the active DMM device to control the measurement type, range, resolution, and various other parameters. Similarly, you can use the NI-SWITCH SFP to identify a switch module, configure the topology, and make individual relay connections.
Tip - Checking Individual Relay States and Counts
Because mechanical relays have a finite lifetime (usually on the order of 10^5 cycles or above), maintaining an accurate count of the number of relays can be important to ensuring test system functionality. Many NI switch modules offer onboard relay count tracking, which you can check via the NI-SWITCH SFP. Figure 4 shows the relay counts of a matrix switch as seen in the NI-SWITCH SFP.
Figure 4. Relay State and Count in the NI-SWITCH Soft Front Panel
Additionally, you can query relay usage programmatically via the NI-SWITCH API in NI LabVIEW software or any other supported programming language. Using programmatic calls, you can set a threshold at which a user is alerted when a certain number of relay cycles have completed, indicating that it is time to check the health of the switch contacts.
Read how to programmatically track relay usage on NI switches.