OmniPlex Neural Recording Data Acquisition System

OmniPlex® Neural Recording Data Acquisition System is Plexon’s flagship electrophysiology (a.k.a. ephys) research system. This system combines front-end amplification and acquisition with intuitive and powerful control and visualization software.

**OmniPlex Release 20 now available. Learn about the new features.

The OmniPlex System is a compact, flexible platform for high performance data acquisition and powerful online spike sorting. It offers low latency, superior common-mode rejection amplification and is well known for its user-friendliness. The OmniPlex System is a combination of the OmniPlex chassis, OmniPlex Software, and for new OmniPlex systems purchased today, a Digital Headstage Processor (DHP) subsystem – all described below. Other versions of the OmniPlex system could utilize an OmniAmp or DigiAmp A/D device.

  • The compact OmniPlex chassis is available in two sizes, Rack Mounted and Table Top, and houses cards for synchronization and timing between system components, acquisition subsystem links, digital inputs, and auxiliary analog inputs for non-neural experiment signals.
  • digital headstage processor for neural recording, omniplex, plexon, ephysThe OmniPlex System Controller operates the OmniPlex Software consisting of OmniPlex Server, the “software engine” for neural signal processing, and PlexControl, which is the main user interface providing data visualization and the user interface for interacting with the system.
  • The Digital Headstage Processor (DHP) for use with digital headstages is Plexon’s most advanced subsystem. The DHP now enables up to 512 channels of neural recording, decreased sensitivity to ambient electrical noise, and lighter headstage cables with fewer wires for greater freedom of animal movement. Further, it offers real-time upsampling to 40KHz and adjustment of multiplexer timing offsets (equivalent to simultaneous sampling) for improved sorting quality, trodal acquisition and software referencing – unlike other digital headstage based systems. Alternatively, the predecessor to the DHP is Plexon’s DigiAmp™ subsystem for analog headstages. The DigiAmp Digitizing Amplifier is available in two sizes: the MiniDigi™ for 16, 32, 48 and 64 channels, and the DigiAmp for 64, 128, 192 and 256 channels. This subsystem is recommended when using analog headstages. Both provide 16-bit A/D conversion at 40kHz per channel for acquisition of the complete wide-band signal. Flexible digital filtering supports a wide variety of filter types (Bessel, Butterworth, Elliptic, 2-12 poles, plus adaptive power line noise filter) and cutoff frequencies, for extracting spikes and field potentials from the wide-band signal and for noise removal.
  • The DHP and the DigiAmp digitizing amplifier are both electrically isolated.

Sorted spike and continuous data acquired by the OmniPlex System is available to external clients (developed through the C/C++ or MATLAB®software development kits (SDKs)) as soon as 1-2 milliseconds after acquisition. This figure is the actual end-to-end latency through the entire OmniPlex System from spike detection input to hardware output, including an online user client program.

The DigiAmps and all modules in the chassis are synchronized via a high-resolution master timing module. The same master timing module can be extended to synchronize timestamps with compatible equipment such as Plexon’s CinePlex® Behavioral Research System.

Plexon offers a variety of analog and digital headstages for various acute or chronic research needs that are suitable for both large and small animals. Including new 64 and the 128 channel high channel count digital headstages with novel Samtec connectors.

Headstage cables are available in a variety of options including: wire gauge, cable wraps, lengths, connectors and configurations. The proper build will improve the quality of your recordings as well as protect your investment. All Plexon headstage cables are reusable.

Plexon offers a range of robust, low-torque commutators that dependably keep multiple types of cables untangled. Commutators have been engineered to optimize signal transfer with specific designs for use with analog headstages, digital headstages and/or optogenetics.

Learn more about the the powerful online spike sorting software for the OmniPlex System that has a flexible and customizable main user interface.

A Plexon Sales Engineer is happy to discuss your needs and how the OmniPlex could best support your ephys research goals.

OmniPlex System Features

Selected technical specifications for the OmniPlex System are provided below. A Plexon Sales Engineer is happy to discuss your needs and how the OmniPlex could best support your neural recording and ephys research goals.

FeaturesSpecifications and Options
– Digital Headstage Processor (DHP) subsystem
– DigiAmp™ Digitizing Amplifier subsystem
– DHP subsystem required for use with digital headstatges
– DigiAmp subsystem required for use with analog headstages
A/D input conversion40kHz per neural channel at 16-bit resolution– Simultaneous sampling
– Continuous wide-band recording
on all neural channels
25µsec (40kHz)
Filtering– Software selectable digital filtering
– 2-12 pole filters, Butterworth,
Bessel or Elliptic; notch filter
For isolation of field potential and spike frequency bands
ReferencingDigital selected channel referencing including:
– Common Average Referencing
(CAR) and
– Common Median Referencing
For online noise and artifact removal
Digital Inputsup to 64 channelsUp to four 16 channel ports, individual TTL and/or strobed word data
Auxiliary non-neural A/D inputs32 channels16 bit A/D conversion for auxiliary non-neural signals, 250kHz max rate (with “fast” card)
Trodal sorting supportStereotrode and tetrode
Channel mapping
User-definable mapping sets
Spike sortingAutomatic online in waveform space or directly in 2D/3D feature space– Waveform space includes
time/voltage using boxes,
templates, lines or bands
– Feature space includes PCA,
peak/valley and more
– Powerful graphical tools for
manually defining and adjusting
sorting parameters online
File type recorded
Plexon .PL2 and .PLX filesUtility provides conversion between formats
Compatibility– Plexon MATLAB®/C++ online and
offline SDKs
– PlexNet (TCP/IP or UDP), and
– NeuroExplorer® online link
Chassis dimensions (inches)Rack Mounted: 7 1/4 x 13 7/8 x 19 1/8

Table Top: 7 1/4 x 12 1/2 x 9 3/4

PlexControl is the powerful online spike sorting software for the OmniPlex System that has a flexible and customizable main user interface. The software represents the next generation in signal visualization and easy-to-use spike waveform classification methods, and allows the researcher to interact with the system. It features easy-to-use signal visualization, spike detection and sorting algorithms. Many spike sorting methods are available including: box, template, line, band sorting in time/voltage space and contour sorting in PCA feature space. A spike waveform snapshot of user-defined size is automatically acquired on each channel by the PlexControl program, and may be viewed at any time to revise spike sorting parameters as necessary. Units can be defined based on either snapshots of the live data or by “drawing” directly on the live data in real time. Each method may be used to sort single electrodes, stereotrodes and tetrodes online.

Continuous spike, field potential and wide-band signals are conveniently displayed in PlexControl’s flexible, customizable user interface along with detected spike waveform segments and their associated two-dimensional (2D) and three-dimensional (3D) feature space clusters for online spike sorting. Additionally, all three data types, as well as thresholded spike waveform segments and digital event data, may be recorded to disk on a per-channel basis.

Check out some of the highlighted features of the software

Line Sorting

2D Polygon Sorting

MultiPlex View

2D and 3D Spectrograms

Ability to Swap Selected Units

OmniPlex Server
The OmniPlex Server is the “engine” under PlexControl. It visually displays each of the various hardware devices (e.g., headstages, amplifier) and software modules (e.g., spike and LFP separators, thresholding, sorting) of the system. It acquires data from the OmniPlex chassis and amplifiers, sends commands to those devices, and implements the software digital signal processing (DSP) for OmniPlex’s filtering, spike detection and spike sorting functions. OmniPlex Server is based on a modular, extensible framework – or topology – hardware and software devices, which are interconnected in a dataflow topology that utilizes a topology wizard to enable users to easily define custom configurations without tedious low-level editing.

The OmniPlex Software is compatible with Plexon’s MATLAB® and C/C++ APIs and Client Development Kits (SDKs), and the online NeuroExplorer® link – enabling low latency, closed-loop experiments and online analysis of live data. It can also be further enhanced by Plexon’s PlexNet protocol supporting remote online data access across any TCP/IP or UDP network, and PlexUtil for modifying the OmniPlex Software output .PLX data files. Additionally, flexible digital filtering functionality in OmniPlex is also incorporated in the Offline Sorter program, enabling the user to apply the same filters offline to continuously sampled data as is used online.

OmniPlex Software, arrives pre-loaded on the control computer with the purchase of any OmniPlex System. A demo version of the OmniPlex Software, which can be run without the OmniPlex hardware, is available at the top of this page.

If you have additional questions, a Plexon Sales Engineer would be more than happy to discuss them with you.

Installation Packages/Upgrades


FeaturesSpecifications and OptionsRemarks
Recording file formatsPlexon (.PL2, .PLX)
Spike detection methodsVoltage threshold
Spike sorting methods– Manual methods include: template,
line sorting, band sorting, box sorting,
2-D polygon sorting
– Automatic methods include: template,
band sorting, 2-D polygon sorting.
Features available for sorting– Projections onto principal components
– For stereotrode and tetrode data,
per-electrode features
Views available– Wideband continuous
– Spike continuous
– Field potentials
– Spike waveforms
– 2D PCA clusters
– 3D PCA clusters
– Stereotrode and tetrode features
– Spike activity
– Firing rate
– Sorted units
– Peak histogram
NEW 3D spike sample histogram
Electrode supportSingle, stereotrode and tetrodeAcquire and online sorting.
PlatformWindows® 7 and Windows® 10
Activation requirementPlexon version-specific hardware license keyWhen OmniPlex® is ordered, it comes with 2 license keys. Additional keys may be purchased.

Manuals/User Guides

Includes features up to Release 18

Post date April 17, 2017


Installation Packages/Upgrades


Support Videos

Change Log

Guides and How To Papers

Analog version only

Technical Specs and Data Sheets

Analog version only


*Must use the OmniPlex Windows 10 Migration Guide in order to upgrade to Windows 10