[figure] [figure]

Midas • M multiple

• I instance

• D data

• A acquisition

• S system Application Independent Components

• Graphical Interface

• Network Interface

• Spectrum Interface Application Specific Components

• Data processing

[figure] [figure]

ExoGam Data Acquisition

Midas - Graphical Interface

Experiment control and monitoring

Diagnostics

Data analysis

• Quick and easy to generate Motif compatible Graphical User Interface

• Designed for use in many varying configurations by a distributed group of implementors

• Common look and feel across all components of the system

• Easy to add new components and safely allows ”user” additions and local modifications

• May be extended without sensible limit

[figure] [figure]

Midas - Network Interface

Network Interface via Register Server - network distributed objects

Allows the GUI to control and monitor the state of the data acquisition equipment and real-time software components

• VXI objects

• VME objects

• CAMAC objects

• software objects (variables and procedures)

The GUI can access all objects (or a selected set) of a given catagory by a single built-in procedure call

[figure] [figure]

ExoGam Data Acquisition

Network Objects

May be dynamically created

Access can use a wide range of ”wild card” features

An object can be

• Hardware register or control within VXI or CAMAC module - addressible to a single bit level

• Portion of VME address space - single location or block

• Variable within control processor software

• Procedure within control processor software

• Any action linked to specific class and object

[figure] [figure]

CAMAC

The following CAMAC ADC modules are currently supported by the Midas package

• LeCroy 4300B ADC

• Silena 4418/V ADC

• Ortec 413 ADC

• Ortec 811 ADC

• Ganelec QDC1612F

Also the following LeCroy CAMAC modules

LC2277 LC2551 LC4208 LC4413 LC4415A LC4434 LC4504 LC4516 LC4518 LC4532 LC2375

[figure] [figure]

Midas - Spectrum Interface

Location independent software interface

• Hardware histograms - real-time ”singles” - from data on DT32 bus

• Software histograms - on-line data analysis

• Offline and Stored disc based histograms

Multiple servers (possibly of different type) may appear as one to the GUI

[figure] [figure]

Electronics

Following Eurogam structure

• Primary detectors interfaced via VXI electronics

• Ancillary detectors may have VXI electronics

• Ancillary detectors may use CAMAC adcs with FERA readout interfaced via the FERA =¿ VXI module (Euroball/Diamant/Bordeaux)

• Eurogam/Euroball Hardware Histogrammer

• Single DT32 bus data source into D2VB module (Eurogam) in VME

[figure] [figure]

VXI control

Each VXI crate contains a Slot 0 (Resource Manager) module (Struck) which has inbuilt a standard VME CPU board. This communicates with the Midas control GUI via ethernet and allows setup and monitoring of all VXI modules in the crate. A logic analyser facility is built-in which can monitor some VXI backplane lines.

Each VXI crate contains a Readout Controller module (Struck STR 8080) which contains a DSP. In addition to code to handle normal readout extensive diagnostic and test facilities are built-in. These allow diagnostics to locate faults within the VXI crate and data generation features to aid system testing.

[figure] [figure]

ExoGam Data Acquisition

Event Processing

Single data stream (follows Eurogam) - hardware event building via DT32 bus.

• Data received via D2VB module (DT32 bus master; 2Mbyte fast RAM; buffer list processing)

• Software checks data for quality; correct format and valid contents

• Reformat to output data format (Eurogam, Euroball or different?)

• Send to Tape Server via high speed broadcast network (fddi or fast ethernet)

• Produce at each step statistical information for monitoring purposes

• At all stages data buffers accessible to GUI for diagnostics

[figure] [figure]

ExoGam Data Acquisition

Tape Server

Manages all output devices • Exabyte

• Digital Linear Tape (DLT)

• Other SCSI devices ?? Features

• Multiple logical data streams

• A data stream may span several output devices

• Online data stream duplication (same data written to several devices)

• Drive performance monitored and available to GUI

[figure] [figure]

Online Analysis

Event blocks sent via the data network from Event Processor to Tape Server are available in ”spy” mode to any number of workstations.

• ”Spy” on the online data non intrusive cannot effect main task of getting data to tape

• ”User” programs running in standard workstations

• Multiple concurrent data analyses possible

• Library subroutines allow histograms to be created for viewing using the Midas Spectrum Viewer

[figure] [figure]

Electronics

Following Euroball structure - multiple data sources

• VXI and FERA via VXI with Hardware Histogrammer as before

• Muliple DT32 bus data sources into D2VB modules (Eurogam) in VME

• Ancillary detectors also use CAMAC adcs with FERA readout interfaced directly to D2VB/HSM

• Other data acquisition systems feeding 16/32 bit ECL bus interfaced via D2VB/HSM or similar can be handled

[figure] [figure]

Electronics

multiple data sources

Additional requirements

• Each data source must tag each event fragment with a global event number

• All data sources must be synchronised so that the data blocks from each data source contain fragments of the same events

[figure] [figure]

Event Building

multiple data sources require that software merge the event fragments to generate complete events

• Check raw data streams

• Convert from specific raw formats to standard FERA - convert VSN/subaddress to group/item

• Generate singles histograms

• Merge event fragments using the global event number tag

Other processing as for a single data source