DAQ system for NA61

Zoltán Fodor

TOF subsystem

Trigger system

Fast start signal

Central event signal

Read out processor

Readout electronics

Start

Fast clear

Trigger unit

Busy signalsfrom other(sub)system

Busy signal

Time diagram of the trigger unit

First start signal, time given by S11

Other busy signals

Delayed start signal

Central trigger for event selection

Fast clear if no coincidence

Start readout

Busy signal

End of readout /from FIC/

General layout

TPC readout

Central DAQ

TOF readout Camac readout

VME, memory modulesPC-VME ???

PSD readout

Busy logic

• The trigger units of the subsystems provide a busy signal

• The concentrators of the TPC readout provide also a busy signal

• If all the system is free to get new event the trigger could start all the readout process independently hardware wise.– The CAMAC and TOF system through own trigger

units– The TPC readout with the gate signal to the

motherboards

CAMAC readout

• Modification– Modify the readout for standalone readout as

the TOF system– We have the trigger unit for the connection to

the FIC– The communication with the central daq

through the memory-card in the same or other VME create connected to the pc with VME-PCI card /has to be checked!!/

Processes

• All the communication with the slow control system is not changed, today also this processor communicates with the DCS and online monitors

• The central PC give the addresses for the subsystem readout /as NA49/

• Event building in the central PC

Differences

• In the NA49 DAQ – the central daq started the readout process for

CAMAC readout.– The memory modules were in the central daq VME

create

• In the NA61 new DAQ– the trigger signal starts the readout.– The memory modules are in the readout creates or in

a separate create for the communication with the PC of the TPC readout

Advantages

• If the central data taking is stopped, the online monitors can get data from subsystems, if the trigger is not blocked

• The subsystems can send data independently from the central system for monitoring, detector control, ….

• Easy to use only the subsystem daq for testing the detectors.