Installing the Optional Auxiliary 12 V Power Source on the PXI-4110

Installing an auxiliary 12 V power source is an optional step that allows you to gain full output power of the isolated channels on the PXI-4110. Compatible auxiliary 12 V power sources must be capable of providing 11 V to 15.5 V and ≥60 W to increase the output current capability of channels 1 and 2 to 1 A. Complete the following steps to install the auxiliary 12 V power source.
Note If available, the PXI-4110 automatically uses the optional auxiliary 12 V power source when the session is opened. To override this feature, use Power Source in the NI-DCPower API within supported sessions. Use the niDCPower Power Source In Use property or the NIDCPOWER_ATTR_POWER_SOURCE_IN_USE attribute to programmatically determine which power source is in use.
Note The auxiliary power source provided by NI uses sufficient wire gauge to maintain voltage requirements for the instrument. If you use a third-party auxiliary power source, you must use the appropriate wire gauge to ensure that it can provide the required current without dropping below the minimum voltage at the auxiliary power input connector. You must use a 11 V to 15.5 V, ≥60 W power source.
  1. Connect the power source to the auxiliary power input connector on the PXI-4110 front panel.
    Figure 8. Installing an Optional Auxiliary 12 V Power Source


  2. Tighten the screws to hold the auxiliary 12 V power source in place.
  3. Connect the 2-position backshell to the device.[1]1 This step is required if you are using a third-party auxiliary power supply. However, the APS-4110 has an overmolded connector. If you are using the APS-4110 as your auxiliary power source, you are not required to use the backshell or the 2-position connector included in the kit.
    Note Using the provided backshell for auxiliary power provides protection against accidental shorts to auxiliary power terminals and strain relief.

Resuming Operation After Auxiliary Power Loss

In case of auxiliary power loss during operation, the isolated output is disabled, and the power supply is shut down to prevent damage to the PXI-4110 and the load. If auxiliary power loss occurs, complete the following steps to resume operation:

  1. Troubleshoot the failure.
    • Verify that all connections, including the front panel connections to the output channels and auxiliary power supply, are secure.
    • Verify that the output channels are enabled. If necessary, use the niDCPower Configure Output Enabled VI or the niDCPower_ConfigureOutputEnabled function to enable the output channels.
    • Inspect the auxiliary input fuse and verify that it is in working condition. If necessary, replace any blown fuses.
  2. Restore auxiliary power.
  3. Reset the power supply using the niDCPower Reset VI or the niDCPower_reset function.
  4. Reconfigure the power supply.

Changing or Removing Auxiliary Power

Complete the following steps to change or remove auxiliary power from the PXI-4110.

Tip It is often more convenient to close the existing session and open a new session when managing auxiliary power state changes.
  1. Disable the output channels.
  2. Disconnect/connect the auxiliary power source.
  3. Reset the power supply using the niDCPower Reset VI or the niDCPower_reset function.
  4. Reconfigure the power supply.

1 This step is required if you are using a third-party auxiliary power supply. However, the APS-4110 has an overmolded connector. If you are using the APS-4110 as your auxiliary power source, you are not required to use the backshell or the 2-position connector included in the kit.