> For the complete documentation index, see [llms.txt](https://docs.axsun.com/axsun-knowledge-base/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.axsun.com/axsun-knowledge-base/how-tos/using-bus-power-for-the-pcie-daq.md). # Using Bus Power for the PCIe DAQ The 900 MS/s version of the Axsun PCIe DAQ (AXP52013-x Rev C or later) can *optionally* draw its power from the host workstation's PSU (power supply unit) via its PCIe edge connector plugged into the workstation motherboard, ***instead of*** an external 12V [AC/DC adapter](/axsun-knowledge-base/ref-manual/ss-oct-laser-engine/accessories.md#ac-dc-power-adapter-and-ac-power-cord) plugged into the power input connector J3 via the [Power-Y cable](/axsun-knowledge-base/ref-manual/ss-oct-laser-engine/accessories.md#power-y-cable). {% hint style="success" %} **NOTE:** It is the user's responsibility to ensure that the host's PSU is adequate to supply up to 25 W to the Axsun PCIe DAQ in addition to the PSU's other connected loads. {% endhint %} To configure the DAQ for PCIe bus-powered operation, install two 2.54 mm jumpers (aka shunts) on the 4-position vertical header J14, which is located in proximity to the PCIe edge connector. The installed jumpers **must** be oriented as indicated by the green rectangles in the photo below. {% hint style="danger" %} **WARNING:** Never attach an external power supply (e.g. 12V AC/DC adapter) to power input connector J3 while jumpers are also installed on J14 on the PCIe DAQ. If J14 jumpers are installed, we recommend installing an unwired "dummy" connector (Molex 43025-0600) into J3 to avoid inadvertently connecting both power sources concurrently. {% endhint %} Jumpers are not supplied by Excelitas, but can be easily procured from various sources, such as [here](https://www.mouser.com/ProductDetail/TE-Connectivity/530153-2?qs=ZDXmSm13591aaDbZi3by6A%3D%3D).

Default configuration with no jumpers installed on J14; power must be delivered to DAQ via external supply on J3 connector.

Two jumpers installed on J14 in the correct orientation (green rectangles); DAQ will be powered by workstation PSU via motherboard.