PL2 Format That Enables Faster Read Time
|June 28, 2013|
If your lab generates large neural data files – you do not want to miss this! Introducing Plexon’s new PL2™ format enabling much faster read time over PLX files – 10, 100 or even 1000 times faster!
When continuous wideband data is being recorded at a 40KHz sample rate, the data rate for 16 bit samples is 288MB per hour per channel. That translates to 36.8 GB/hour for 128 channels and 73.7 GB/hour for 256 channels – not including other types of data or file system overhead. The file size can quickly become unwieldy. Even when not recording wideband data, the files can become quite large when the channel count is high. Accordingly, these large, high-resolution files can take a very long time to load for analysis.
To address this issue, Plexon has taken the lead, once again, and advanced its original industry-standard recording format to develop a game-changing new file format – PL2 – that significantly improves the efficiency of the analysis process.
The PL2 file format:
- Is significantly faster in single channel read time depending on file length, types of data, and number of channels. Individual channels can be loaded from files hundreds or even thousands of times faster.
- Enables up to 50% faster block level reads, as in reading the file sequentially.
- Is a more general format representing all existing PLX data plus more channels and additional types of data including system configuration and individual channel metadata.
- Generates a somewhat smaller file size compared to Plexon’s previous PLX format.
- Is recorded in real time by Plexon’s OmniPlex® Neural Data Acquisition System .
- Requires OmniPlex Software v1.9 or later.
- Is an option – researchers can choose to record using either the new PL2 format or the original PLX format.
- Can be created by converting an existing PLX file using PlexUtil 4.0.
According to researcher Nick Steinmetz, Stanford University, “For very large recordings I have made (32 channels, several hours duration, 40kHz sampling rate, as large as 50GB), reading data into MATLAB was very time consuming using the old PLX data format. By converting to the new PL2 format, these files can now be read extremely efficiently, enabling some analyses I couldn’t otherwise perform. Using PL2 has been a fantastic improvement!”
Learn more in our white paper PL2 File System Overview . The suite of PL2-compatible software (including OmniPlex 1.9, PlexUtil 4.0 ,Offline Sorter™ 3.3 ,NeuroExplorer® 4.125 and new PL2 SDKs ) is now available online and can be downloaded from the website’s Support section, Software Downloads area. With the appropriate version license key for the corresponding software program, these PL2-compatible releases are available free of charge.
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Record PL2 Files with OmniPlex v1.9
At the heart of the PL2 launch is the newest software release for the OmniPlex Neural Data Acquisition System. OmniPlex Software v1.9 now records files in the both the original PLX and new PL2 formats, and reduces client latency for DigiAmp™ systems to ~1ms! You are empowered to acquire and analyze data faster than ever before!
The new PL2 format significantly improves efficiency of analysis of large, high-resolution neural data files. In tests, a file containing ten minutes of spike (SPK), wideband (WB), and field potential (FP) data from 256 channels was recorded in both PLX (13.8GB file) and PL2 (11.4GB file) formats. Single channel reads as performed by Offline Sorter™ and MATLAB® programs resulted in the following:
Not only does OmniPlex v1.9 now enable ultrafast data loading for analysis through PL2, but combined with a DigiAmp (64 through 256 channels) or MiniDigi™ (16 through 64 channels) Digitizing Amplifier, it yields an almost negligible system latency of ~1ms. This figure is the actual end-to-end latency through the entire OmniPlex System from spike input through an online user client program to a hardware output.
OmniPlex Software v1.9 further offers a breadth of added, expanded or improved functionality including new features for stereotrode and tetrode users. To compliment the significant advancement of the OmniPlex software, Plexon has developed the new OmniPlex Neural Data Acquisition System User Guide that offers a wealth of new information, step-by-step instructions and tips for better results.
Convert PLX to PL2 with PlexUtil 4.0
PlexUtil is Plexon’s file utility program that permits the manipulation of neural data files such as creating subsets of data and/or merging data.
PlexUtil version 4.0 is an important component of the new, game-changing PL2 file format launch. PlexUtil 4.0 will enable researchers to convert their PLX files into PL2 files, accessing the ability to load large neural data files faster than ever. Researchers wishing to convert PLX to PL2 files will need to do the following two things:
Upgrading the license keys is a simple process. Researchers should email firstname.lastname@example.org with their OmniPlex and/or MAP System license key serial numbers (found on the back of the key after the “SN:”) and request the PL2 upgrade codes. Plexon will reply with the codes and further instructions. With the upgraded license keys and PlexUtil 4.0 running on the computer, researchers will be ready to convert files.
Sort PL2 Files with Offline Sorter 3.3
Offline Sorter is the most recognized and trusted offline spike sorting software in the industry today, with more than 800 publications specifically citing its use. In addition to reading Plexon file types, it reads file types from many data acquisition systems and software programs across the industry.
Its newest release necessary for reading PL2 files, Offline Sorter 3.3, now reads PL2 files! The PL2 format benefits will be most evident when loading large data into Offline Sorter becomes hundreds or even thousands of times faster.
In addition to the added PL2 functionality, Offline Sorter v3.3 is packed with new features and improvements including a new tool to invalidate high-amplitude artifacts; a completely re-written Waveforms View for much faster rendering of large numbers of waveforms; the addition of alignment during waveform extraction; support for enhanced PCA; the ability to define Time Segments interactively and invalidate waveforms in the current segment via the Timeline View right click menu; and much more.
Offline Sorter 3.3 can be downloaded online free of charge for those with an Offline Sorter v3 license key. If you do not have a license key for version 3, this is an excellent time to upgrade. Take advantage of the 30th Year Anniversary promotions . For more information, email email@example.com.
Analyze PL2 Files with NeuroExplorer 4.125
Let us know about your 2013 publication citing Plexon and our equipment and we will send you a thank you award with a mug and a T-shirt! Send notices, address and T-shirt size to firstname.lastname@example.org.
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