PAS-Home Cage

San Diego Instruments: PAS-Home Cage| SDI Photobeam Activity Systems

Get the most accurate qualitative analysis of mouse or rat home cage activity with Photobeam Activity System-Home Cage (PAS-HC).

Unlike other systems, your subject’s locomotor activity will be precisely tracked by a 4×8 photobeam configuration that reports breaks in real time, requiring no special calibration.

Test up to 48 stations at a time for as long as seven days-or 24 when using the option rearing frame-and set it all up quickly with no technical knowledge required.


  • Capture the most accurate beam breaks with the 4x8 photobeam configuration
  • Record all beam interruptions and patterns, including x,y positions
  • Test for 7 days without human intervention
  • Set up the menu-driven software in minutes
  • Easily assemble up to 64 test stations easily using color-coded Ethernet cables
  • Use the optional rearing frame for up to 32 test stations


Frame Dimensions

Inside Dimensions:  10" (W) x 18.5" (L) Outside Dimensions: 11.5" (W) x 20" (L)


4 lbs.


Stainless Steel Frames 

Maximum # Stations

32 (with rearing)

Note: It is possible to add one more PAS Distribution Box to double the number of configurable stations.

PAS Distribution Box

11.75" (W) x 18.75" (L)

# of Photobeams

4 x 8

Photobeam Spacing

1 15⁄16"

Optional Rearing Frame

Frame dimensions as above with 1" photobeam spacing

Standard Cable Length

12 ft.


FDA CFR Part 11


  • PAS-Home Cage frame with photobeams
  • Adjustable vertical rods for frame height
  • PAS-Home Cage photobeam application software
  • PAS Distribution Box
  • PC interface board
  • Cables & connectors
  • User manual

About SDI’s Photobeam Activity System- Home Cage (PAS-HC)

SDI’s Photobeam Activity System- Home Cage (PAS-HC) is designed to provide an affordable locomotor activity system that offers the greatest amount of flexibility and most accurate qualitative analysis of mouse or rat home cage activity.

A 4x8 photobeam configuration precisely tracks the animal’s locomotor activity to ensure you don’t miss any important movement data. Plus, unlike competitors, all beam breaks are reported in real time so no special calibrators are required to measure locomotor behavior.

A unique feature to SDI’s PAS-HC system is the PAS software.  The software accurately records all beam interruptions, central peripheral activity, ambulation movements, fine movements, rearing, and time stamped (x,y) positions—giving you the ability to measure locomotor activity at any level of detail needed. It will also store your data in a single file providing exceptionally easy export and analysis.

Made to be flexible for your needs, the PAS-HC is adaptable from one test station up to 48, and can accommodate up to 24 stations when the optional rearing frame is put into place.

The home cage system is designed using a lab-standard transparent acrylic cage, keeping it an affordable choice for home cage testing. In addition, SDI’s Home Cage enclosure is well suited for long term activity tests where food and water are required.

Highlights of the PAS-Home Cage Include:

Track Movement More Accurately than with Other Systems

The PAS Home Cage system uses a 4x8 photobeam array to accurately track the movement of the animal.  As the software calculates the animals x, y coordinates provided by the beams, the animal’s tracking is available for viewing on your screen.  Many other systems just use a motion sensor or single axis beam sets, which rob you of valuable data.

Meet the Needs of Circadian Rhythm Tests

Run a maximum configuration (up to 48 stations) for up to seven days without human intervention.  This long term ability assures that the PAS Home Cage can meet the needs of circadian rhythm tests.

Obtain Qualitative Data Not Found in Other Systems

The PAS software utilizes the total beam pattern to calculate the centroid position of the animal and makes your center/peripheral results available for analysis, along with the ability to apply zone maps to the data.  Determine distance, speed, resting time—and even zone entries and time in zone—for a comprehensive scope of data available for analysis.

The Most Accurate, Easy-to-Use Software Available

Your PAS software will add significant flexibility and accuracy to your study. Not only is all of your data saved in one, easily accessed file—but you can define your complete study in advance by pre-assigning animals to specific stations for each session, and then assigning a predefined protocol to every test session. 

The software will automatically record your session data and keep it all together in the study’s single file. When you are ready, display your data right on your computer monitor or choose to export it with one click to Microsoft® Excel or to a delimited file type(TAB, CSV, etc.). 

Other software features include:

  • Define Your Study in Advance

    Make sure you collect the most accurate data possible by defining each of your planned test sessions. You will be able to plan session parameters, set subject identifiers, assign subjects to specific test stations, and specify subject parameters such as dose level.  To keep from losing any critical data, it will all be stored in a single file format.

  • Automatically Run Sessions

    Defining your study in advance not only saves you time by automating sessions, but eliminates run time decisions and data entry that can cause mistakes. You’ll also ensure your results are tightly coupled to your predefined subject identifiers. Simply follow the PAS software instructions to execute the test session.

  • Real Time Beam Break Display

    Assure the accuracy of your operation with a real time display of beam breaks—which gives you a visual representation of the animal’s activity patterns. Other systems rely on blinking lights on the frames to give you a status but this does not give you a visual indicator of the activity pattern.

    Beam breaks are automatically categorized as "ambulations,” "fine movements," or “rearing” and are based on distance moved, not duration of time, further ensuring accuracy in your results.

  • Export Directly to Microsoft® Excel (or any delimited file type)

    The PAS software makes table formatted results available for direct export to Microsoft® Excel or to a delimited file type(TAB, CSV, etc.) and automatically identifies data by column headers.  Since the data is exported from a single file, you won’t lose critical information and you’ll save time by removing the need to aggregate multiple single files and possibly reformat them again.

  • Connect without Complications

    To make your connection as easy as possible, the PAS-HC uses standard Ethernet cables, color-coded yellow and blue, along with color-coded frame and control box connections.  In addition, all of the data cables from the control box to the PC data are numbered. Using these two approaches helps you avoid confusion and mistakes when connecting your PAS equipment.

System Components Include:

  • 4 x 8 Photobeam Mounting Frame
  • Control Unit
  • Software
  • User Manual
  • All Cables and Connectors


Q: I have installed the PAS software and I’m getting no communication.

A: Go to the Windows Device Manager Screen and check to see if the Acces I/O card is listed there. If not, reboot or reinstall the Acces drivers.

Q: What is the maximum session time using PAS?

A: 24 hours. Multiple sessions of up to 24 hours each can be stored in a single experiment database.

Q: What is the difference between Cage Rack Photobeam and Cage Rack Flex-Field software?

A: Cage Rack Photobeam is a general activity system that measures activity on only one axis. The Cage Rack Flex-Field is for more detailed activity testing. The system measures activity in two axes and provides data that can be used to create a track of the activity and provide time and distance data. Zone maps can be applied to the data for varying analysis.

Q: Does SDI’s Flex-Field system cover the Open Field paradigm?

A: Yes, with additional capabilities to support other types of experimental paradigms.

Q: What is the maximum number of enclosures for the Cage Rack Photobeam System?

A: It depends on the frame type used but at least 32. Please refer to product data sheets for specific details.

Q: I replaced my computer that was running the Microsoft Windows ® PAS software. After I re-installed PAS on my new computer, nothing worked. Why?

A: The Microsoft Windows operating system must be either the Windows 2000 or Windows XP version. Make sure that the ACESS I/O card has been installed in the new computer, the driver has been re-installed and the correct board type has been selected during the installation process. Make sure you install the driver before you install PAS. Check to be sure that Windows recognizes the new board by using the Device Manager to check for a Data Acquisition entry. If the board is not present, de-install and re-install it. You must have the correct driver version. WIN 2000 and XP require at least ACCES I/O Driver Version 5.x. Earlier versions will not work. The latest drivers can be downloaded from Acces I/O. Reboot your computer between the driver install and the PAS install. Reboot after the PAS install.