To achieve the optimum power output from the system and accommodate the power demand for applications, connect the cDAQ-9189 to an external power source.

Notice To ensure the specified EMC performance, do not connect the power input to a DC mains supply or to any supply requiring a connecting cable longer than 3 m (10 ft). A DC mains supply is a local DC electricity supply network in the infrastructure of a site or building.

The cDAQ chassis requires an external power source as described in the Power Requirements section of the specifications document for your chassis. Some suggested NI power supplies are listed in Part Numbers for Recommended Cables and Accessories. The cDAQ chassis filters and regulates the supplied power and provides power to all of the modules. The green POWER LED on the front panel identifies when the power input is in use.

Complete the following steps to connect a power source to the cDAQ chassis.

  1. Make sure the power source is turned off.
  2. If connected, loosen the connector screw flanges and remove the power screw terminal connector plug from the cDAQ chassis. The following figure shows the terminal screws, which secure the wires in the screw terminals, and the connector screw flanges, which secure the connector plug on the front panel.
    Figure 6. Power Screw Terminal Connector Plug
    1. V (Positive) Terminal Screw
    2. C (Negative) Terminal Screw
    3. Connector Screw Flanges
    Caution Do not tighten or loosen the terminal screws on the power connector while the power is on.
  3. Connect the positive lead of the power source to the V terminal of the power connector plug and tighten the terminal screw.
  4. Connect the negative lead of the power source to the C terminal of the power screw terminal connector plug and tighten the terminal screw.
  5. Install the power connector plug on the front panel of the cDAQ chassis and tighten the connector screw flanges.
  6. Turn on the external power source.

If the power source is connected to the power connector using long wiring with high DC resistance, the voltage at the power connector may be significantly lower than the specified voltage of the power source.

Refer to the Power Requirements section of the cDAQ-9189 Specifications for information about the power supply input range. Refer to the Safety Voltages section of the cDAQ-9189 Specifications for information about the maximum voltage from terminal to chassis ground.