16-bit 125 MS/s
2740 Digitizer Family
Overview
The 2740 Digitizer is a 64-channel digital signal processor for radiation detectors available in VME64 (V2740), VME64X (VX2740), and Desktop (DT2740) form factor. It offers not only waveform digitization and recording but also Multi-Channel Analysis for nuclear spectroscopy using Silicon strip, segmented HPGe, Scintillation detector with PMTs, Wire Chambers, and others. The 2740 can perform pulse height measurements (PHA), constant fraction timing (CFD), charge integration (QDC) and pulse shape discrimination (PSD) independently for each of the 64 channels.
Analog input channels are provided differential (on 2740 versions) or single-ended (on 2740B versions). Each channel of the module digitizes the analog input, that can be the signal coming from a physics detector, with a 16 bit, 125 MS/s ADC. The sampled data are used to initiate the digital pulse processing sequence, managed in the FPGA at the firmware level. Different firmware types can be selected via software, according to the specific setup and acquisition mode.
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Common trigger: all channels acquire simultaneously with a common trigger. The trigger can be fed externally or generated by a combination of individual channel discriminators. This mode is mainly intended for the acquisition of waveforms, like a digital oscilloscope. Options for zero suppression are available to remove not significant data.
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Independent trigger: suited for trigger-less applications, where no global trigger is needed but each channel acquires waveforms upon its self-trigger which fires through a digital discriminator, independently of the others.
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DPP: real-time processing in the FPGA allows for the extraction of physical parameters from the waveform (e.g. pulse height, charge, timestamp, PSD), well suited for high counting rate applications. It is yet possible to save both raw waves and parameters.
Highlights
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High channel density: 64-channel, 125MS/s 16-bit ADC with individual DC offset adjustment
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Digital pulse processing and waveform recording of 64 independent detectors
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High-resolution Nuclear Spectroscopy: multiport MCA operating in PHA, PSD modes
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Open FPGA architecture for pulse analysis algorithm customization
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Easy synchronization of multiple units
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Front panel readout via USB-3.0 type-C or 1/10 Gigabit Ethernet
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Use-friendly readout software for multiparametric spectroscopy (CoMPASS) or waveform recording (WaveDump2)
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Firmware/software generator and compiler for the Open FPGA (Sci-Compiler), not requiring FPGA programming skills
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Onboard Zynqยฎ UltraScale+โข MPSoC integrating an Armยฎ-based CPU running Linuxยฎ
16-bit 125 MS/s Models
VX2740
64 Input Channel 16 bit 125 MS/s Digitizer
DT2740
64 Input Channel 16 bit 125 MS/s Digitizer
V2740
64 Channel 16 bit 125 MS/s Digitizer
Image |
Name
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Resolution (bits) | Max Sampling Rate (MS/s) | No. of Channels | Package | Bandwidth (MHz) | Full Scale Range (V) | Board Memory (Samples/ch) | Analog Input Connectors | CAEN firmware | Open FPGA | |
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VX2740 |
16 | 125 | 64 | VME64X | 50 | 2 | 21 M | 2mm 40-pin header male | DPP-PHA, D-SCOPE, DPP-PSD, DPP-ZLEplus(cs) | YES | |
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DT2740 |
16 | 125 | 64 | Desktop | 50 | 2 | 21 M | 2mm 40-pin header male | DPP-PHA, DPP-PSD, D-SCOPE, DPP-ZLEplus(cs) | YES | |
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V2740 |
16 | 125 | 64 | VME | 50 | 2 | 21 M | 2mm 40-pin header male | DPP-PHA, DPP-PSD, D-SCOPE, DPP-ZLEplus(cs) | YES |
Interfaces & I/O
USB
An USB-3.0 (tested up to 280 MB/s) type C link is provided in all form factors for an easy data readout.
Ethernet
The DT2740, VX2740 and V2740 models mount a SFP+ receptacle supporting 1 Gb Ethernet tested up to 110 MB/s or 10 Gb Ethernet (UDP) up to 850 MB/s on Copper RJ45 or optical LC transceiver. A RJ45 1GbE transceiver and a spare optical LC 10GbE one are provided with the board.
Digital I/O
A set of sinlge-ended (NIM/TTL) digital I/Os on the front panel can be programmed for common and individual trigger propagation to external trigger logic, scaling up the acquisition input channels where a global trigger generation is mandatory. They can also be configured for sync, start and stop distribution in a multi-board system.
Data Acquisition
CAEN digitizers support multiple data acquisition modes, implemented as distinct FPGA firmware solutions, making them adaptable to a wide range of radiation detection applications in Nuclear Physics.
The CAEN 2740 Digitizer Family features 64 s input channels, each capable of digitizing detector signals using a 16-bit ADC at 125 MS/s. Data acquisition is driven by trigger signal generation and the identification of a Region of Interest (ROI), defined in terms of sample count or time duration. Trigger sources can be local (channel self-trigger), external, or software-based. Once acquired, the digitized data is processed within the FPGA, stored in high-speed memory as eventsโincluding Trigger ID and Timestamp tagsโand then transferred via high-bandwidth communication interfaces for further analysis. The digitizer supports different acquisition modes, designed to balance throughput, latency, and data efficiency according to experimental requirements:
-> Triggered Mode: All channels acquire data simultaneously upon a global trigger generated by a Central Logic Unit, which processes local triggers from individual channels. External and software triggers can also be configured as sources for the global trigger. Zero suppression algorithms can be applied to remove non-significant data and reduce the readout payload.
-> Streaming Readout Mode: Each channel autonomously identifies its ROI using the self-trigger mechanism, acquiring data independently of the other channels. This mode includes automatic zero suppression (non-triggered channels are not acquired), maximizes acquisition rates, and is ideal for applications requiring real-time parameter extraction. In addition, correlation logics can be configured to validate event acquisition upon coincidences or anticoincidences between local and external triggers.
CoMPASS multiparametric software
CAEN Multi-Parameter Spectroscopy Software (CoMPASS) is the DAQ software from CAEN able to implement a Multiparametric Data Acquisition for Physics Applications: the detectors can be connected directly to the digitizers/MCAs inputs and the software acquires energy, timing, and PSD spectra at the same time.
-> Simultaneous plot of waveforms, Time, Energy, PSD, and TOF spectra
-> Online filtering (Time, Energy, PSD)
-> Multi-board management
-> Advanced data saving
-> Root format data saving
Wavedump2 software
WaveDump2 software specifically supports the Scope firmware of the27xx Digitizer families for waveform recording applications. Data acquisition from multiple boards and multi-board synchronized systems are managed through a dedicated toolbar.
-> Multi-board management
-> Simultaneous plot of waveforms from up to 8 input channels
-> Flexible and easy configuration of channel and trigger settings
-> FFT analysis
CAEN ToolBOX
CAEN Toolbox is a software utility designed to upgrade and manage the ๏ฌrmware on the 27xx Digitizer Familes. Moreover, this highly versatile software suite supports a wide selection of CAEN devices, including front-end boards, Digitizer 1.0 and 2.0 series, bridges and controllers, PLU, and power supplies. It o๏ฌers a user-friendly GUI or command line application to manage onboard ๏ฌrmware, perform debug tests, and execute other useful functions.
CAEN FELib Library
The CAEN x27xx waveform digitizers introduce a new approach to accessing firmware parameters by abstracting register-level controls into user-friendly library parameters. This simplifies the development of custom DAQ systems and software.
Control and data acquisition are managed through CAEN FELib, a cross-platform interface compatible with Windowsยฎ and Linuxยฎ (x86 and ARM). However, FELib itself does not support any specific digitizer family; users must also install the corresponding CAEN Digx library for their device.
-> Set of functions designed for controlling and utilizing Digitizers 2.0
-> Available in C/C++ and Python for both Windows and Linux operating systems
-> Distributed as an open-source software under GNU LGPL v3 license
WEB Interface
The Digitizer 27xx includes an integrated Web Interface that enables direct access to essential service functions via a standard web browser, without requiring external software. Key features include:
-> Real-time hardware status monitoring, with visibility on operating parameters and error notifications
-> Network configuration, supporting both manual IP assignment and DHCP
-> Firmware management, allowing upgrades and version selection directly from the interface
-> Advanced configuration options, such as PLL control for precise internal clock synchronization
-> Access via USB or Ethernet, with credential-based authentication supporting multiple user roles (administrator and standard user)
Sci-Compiler
The 27xx digitizer family can be programmed through the Sci-Compiler software for easy-FPGA programming. It is a block-diagram-based graphic tool, thought to help non-expert VHDL coders in building their own firmware. Each block defines an operational function (like a logic port, a trigger, a discriminator, a counter โฆ) and more blocks can be wired together to build a complex FPGA code, so that it is possible to speed up the programming effort and get quickly to the testing and using phase.
Form Factor Interchange
x2740 digitizers introduce a form factor interchange additional feature, useful for efficiently commuting from laboratory experience to the experimental setup and vice versa.
The DT2740 Desktop digitizer can optionally be transformed in a 19″ rack mount board in few steps (rack mount kit included!).
The V/VX2740 VME digitizer may be turned into Desktop just plugging it into the single-slot VME64X u-crate.
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