Fault Insertion Units (FIUs) are designed to insert fault conditions between automated test equipment and devices under test (DUTs). In a FIU’s default setting, DUT signal lines are connected to the test equipment directly through the FIU module. To insert a fault condition, the unit configures internal relays to create short-circuit connections and open circuits. The following are fault conditions commonly used in today’s automated test applications:
The NI PXI-2586 is a high-power, general-purpose switch in a single-slot, 3U PXI module. It has 10 independent SPST (Form A) relays, as can be seen in Figure 1, with low contact resistance and high isolation voltage. The module is rated for both high currents (up to 12 A) and high voltages (up to 300 VDC/300 VAC), and is ideal for switching power signals and loads in control applications and battery, power supply, and automotive testing.Figure 1: NI PXI-2586 Power-On State
One or more NI PXI-2586 modules can be used to create a variety of different 12 A FIU topologies. This white paper shows how to create and use the following topologies:
The topologies are created by externally connecting the NI PXI-2586 channel and COM pins. The connections between pins can be made when assembling your cable harness or can be managed on any custom fixture or PCB required for your DUT.
One NI PXI-2586 10-Channel, 12 A SPST switch module can be used to create a 3-channel FIU with the ability to apply 2 simultaneous fault conditions. Figures 2 through 5 show the resulting 3-channel FIU’s default configuration, as well as the FIU’s open and short circuit fault conditions.Figure 2: 3 Ch, 12 A FIU with 2 Fault Buses - Default ConfigurationFigure 3: Open Circuit Fault – DUT 0Figure 4: Pin to Pin Short – DUT 0 and DUT 2Figure 5: External Fault (such as Vbatt or GND) – DUT 0 and FAULT 1Connect the channel and COM pins of the NI PXI-2586 as shown in Table 1 and Figure 6 to build the 3-channel FIU topology:
Pins to Short
Color in Pinout
Ch0, Ch5, COM7
Ch1, Ch4, COM8
Ch2, Ch3, COM9
Figure 7: 4-Ch FIU with 1 Fault Bus, 2 Selectable External Faults - Default Configuration
To build a 4-channel FIU with 1 fault bus and the ability to select between two external fault conditions, short-circuit the channel and COM pins as shown in Table 2 and Figure 8.
Table 2: 4-Ch FIU - Pins to Short (Table)
Figure 9: 9-Ch FIU with 1 Fault Bus, 2 Selectable External Faults - Default Configuration
To build a 9-channel FIU with 1 fault bus and the ability to select between two external fault conditions, use 2 NI PXI-2586 modules and short-circuit the channel and COM pins as shown in Table 3 and Figure 10.
Note that there are COM pins from both devices that are to be connected together. Additionally, note that the same-colored solid and ringed pins are not to be connected together.
Collaborate with other users in our discussion forums
A valid service agreement may be required, and support options vary by country.