DAQ system: Difference between revisions

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poly 902 339 966 285 1034 321 976 356 [[DAQ Power Supply]]
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poly 1021 274 1081 225 1140 242 1089 293 [[DAQ Power Supply]]
 
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Gammasphere's DAQ system (data acquisition system) is now placed on relay racks by each of its four "hemispheres". Each of the racks for the DAQ consists of a [[DAQ Power Supply|power supply]], a [[Collector Box|collector box]], and a [[VME Crates|VME crate]]. The data acquisition system observes, interprets, and modifies data taken from [[Gammasphere]] and appropriately presents it to the user.   
Gammasphere's DAQ system (data acquisition system) is now placed on relay racks by each of its four "hemispheres". Each of the racks for the DAQ consists of a [[DAQ Power Supply|power supply]], a [[Collector Box|collector box]], and a [[VME Crates|VME crate]]. The data acquisition system observes, interprets, and modifies data taken from [[Gammasphere]] and appropriately presents it to the user.   

Revision as of 19:13, February 28, 2023

VME CratesVME CratesVME CratesCollector BoxCollector BoxCollector BoxDAQ Power SupplyDAQ Power SupplyDAQ Power SupplyDAQ Power SupplyLiquid Nitrogen
Figure 1. DAQ System circled in red; one rack for each of the four "hemispheres" of Gammasphere

Gammasphere's DAQ system (data acquisition system) is now placed on relay racks by each of its four "hemispheres". Each of the racks for the DAQ consists of a power supply, a collector box, and a VME crate. The data acquisition system observes, interprets, and modifies data taken from Gammasphere and appropriately presents it to the user.

When Gammasphere collects data, single-ended signals are first collected from the slope box for the Ge Center, Ge Sides, and BGO segment. The signals are converted to differential signals by the SBX, and are then sent to the collector box so the signals can properly be routed to the digitizers. The digitizers process and output the desired information to the user based upon their data specifications. The DAQ system is an FPGA-based design that provides communication hub interfacing the preamp, power board, dongle and slope box to EPICS through serial interface. Analog signal paths are completely software controlled.

DAQ System Function

The DAQ system prior to upgrades consisted of VME crates, IOC Modules, Digitizers and Trigger Modules. There were two types of Digitizers (Master and Slave) and well as Trigger (Master and Router). In the current version of the upgraded Gammasphere DAQ system, some of the old hardware is still used, but in a different way. All channels in all digitizers run continuously. When discriminator logic marks leading edges of gamma-ray signals, energy sums, timing and other data are stored in a header identifying the event. If the event is selected for readout by the trigger system, the header and a programmable amount of waveform is transferred from the channel to the board-wide FIFO (first in, first out) data holder. The IOC scans the FIFOs to see if there is data to read out. If so, the IOC reads it out into buffers. A program called “gtReceiver” sends messages to each IOC when the receiver is ready for more data. The IOC then breaks apart buffers into UDP packets and sends them to gtReceiver. The gtReceiver program then routes the packets to files that may be organized by digitizer or by channel.

Gammasphere DetectorsGammasphere DetectorsGammasphere DetectorsThe Slope BoxThe Slope BoxThe Slope BoxThe Slope Box ExtensionThe Slope Box ExtensionThe Slope Box Extension
Figure 2. Diagram of the DAQ system process.

DGS Commander EPICS Screens

This section contains an image map of DGS Commander and all subsequent EPICS screens.

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