PS12DC Datasheet | LabJack
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PS12DC Datasheet

PS12DC Datasheet Overview

The PS12DC is a power switching board designed for medium to low current DC power switching applications.  Controlled through 12 digital outputs, the board can switch power sources ranging from 5 to 28V DC.  Attach the PS12DC to the DB15 connector presented on all compatible devices, and toggle the states of the EIO and CIO digital output lines to turn the switches on/off.  This device requires at least one compatible power supply, and a multi-channel digital output source, such as a LabJack, or Arduino.



  • 12 digitally controlled switches with LED indicators
  • Optical isolation
  • Handles 5 - 28 Volt supply
  • Up to 750mA/chan
  • Thermal (self-resetting) fuse protection
  • Flyback protection
  • Snaptrack/DIN-rail compatible, with TE Connectivity P/N TKAD

Compatible Devices

Typical Applications 

  • Solenoid Valves/Actuators
  • Relays
  • Simple DC Motors*
  • Horns/Bells/Alarms
  • Blowers/Fans
  • Low Voltage DC Lighting
  • LED Drivers
*If using a larger DC motor (above 12V DC, or bigger than 1" diameter as a general rule), we recommend installing supplementary snubber diodes, and inrush limiters, as large flyback and inrush currents can overwhelm the protection circuitry on the PS12DC, resulting in damage. Basically just buy a few of these $0.80 parts, and put one in series with each motor. See the end of Appendix D for details.

How To Use

You will need a LabJack, a PS12DC, and something to control.  The diagram below demonstrates how to make connections for controlling a DC motor, and a fan.

  • Option A - Items are powered by 5V power supply (VS) located on the LabJack, this is the most basic connection.  
  • Option B - Items are powered by 12V external power supply.
  • More Options - See  Appendix A - Wiring Diagrams


Once the wires are attached, turn the DC Motor on and off by toggling the state of the appropriate digital control line.  When the control IO is output-low, S0 will sit at 0V.  When the control IO is output-high, S0 will be at the voltage connected to VS1.  Look at the IO Reference table below to identify which control line to toggle.  The DC motor is connected to S0, so that means a state change in EIO0 will turn it on and off.

Table 1. Digital I/O pins for each switch

Switch # Digital IO
S10 CIO2
S11 CIO3


If the PS12DC is attached to the LabJack differently than in the picture above, there will be a different corresponding digital IO line.  The full pinout details can be seen in Appendix C - Pinout Info .

Download LJControlPanel to get started, or create a program in one of our supported languages to communicate with the LabJack.  It will also be necessary to install the UD driver, so the LabJack is recognized over USB.

Other Compatible Devices

Connect a PS12DC to any device with 3.3V to 5V digital outputs through the use of the P3 pin header.  This includes Arduino, homemade boards, PCI DAQ boards, etc.  Please note that when using other digital output boards, support is limited to the PS12DC.  The image below shows an example of how to connect a PS12DC to an Arduino.




The Arduino has 14 digital IO pins, the first 12 are connected to the PS12DC, and the two GND wires on the PS12DC are tied to GND on the Arduino.
Multiple PS12DC boards can be connected to a single compatible LabJack, as shown in the image below.  See Appendix B - Connection Options for more information.



If there are problems with the PS12DC, ensure the following:

  1. There is a working power supply (5 to 28V) connected to one of the power supply blocks, e.g. VS1/GND1.  Connect wires to VS as shown below if no power supply is available.
  2. The switch number under inspection is being powered.  For instance, if checking S8, verify that VS5/GND5 are connected to a working power supply.
  3. Verify that the LEDs turn on and off when the digital output states on the LabJack are toggled high and low.  This can be accomplished by opening LJControlPanel (for U3, U6, or UE9) or Kipling (for T-series), and checking/un-checking the boxes next to the digital output of interest[1].  Or download the test program (U3, U6, or UE9 only):
[1] To test operation of the PS12DC on T-series devices navigate to the Dashboard tab of Kipling; the Register Matrix is less useful for testing the PS12DC compared to the dashboard. From the Dashboard tab set the IO of interest (See the pinout info page) to "Output" and toggle the High/Low selection. When set "High" the LED next to the corresponding switch on the PS12DC should light up.

Drawings and CAD models


Can P1 and P3 connectors be utilized at the same time, allowing multiple inputs.  For example, a PS12DC connected to U6Pro thru P1 (standard connection), and then the U6Pro +5V terminal connected through an external toggle switch to the PS12DC P3 DI0.  Would this allow both the toggle switch and U6Pro EIO0 to turn a device connected to PS12DC S0 on and off, in a logical 'OR' type fashion.

Can the PS12DC be used with the T7? Nowhere in the documentation that I could find does it say it is compatible. If so, can it be used with either the DB37 or the DB15 connectors on the T7 like it is the the U6/UE9? Finally, from a quick look at the datasheet of the MUX80, it seems it can only be used for analog input, not digital output. That being said, is there any way to hack it to also control the states on four PS12DC boards attached to a MUX80 on a T7?

The PS12DC can be used with a T7, and the datasheet has been updated to accordingly. It can be used in the same way as on the U6/UE9. 

Regarding the Mux80 - it is not a Digital I/O multiplexing board, so there's no way to combine it for extra PS12DC boards - even if the physical connectors seem to match up.  If you are looking for a low-cost method to use four PS12DC boards, consider that two U3-LVs and four PS12DC boards will give a total of 44 channels (only 4 less than if you used two UE9 or T7). You'd have to wire the PS12DCs according to the image in Appendix B of the PS12DC datasheet.

Better to have a pic w/ T7,  and more information w/ T7 will be much better.

Are you referring to the troubleshooting section?  The T7 has the same digital I/O lines as the U6 and UE9, so I don't know that it's necessary to include anything special about the T7, but maybe the troubleshooting section should include instructions for the T7 software?