How to structure your readout

How to structure your readout

Before describing how to modify the readout software, it is important to understand how the readout software organizes the readout. There are two organizations to consider; The logical way in which you programmatically desribe the readout to the software, and the physical layout of the corresponding event in the event buffer.

The new NSCL readout software logically organizes events in chunks. Each chunk is called an Event Segment. The framework supports three types of event segements:

Simple Described by objects that are derived from the class CEventSegment.

Compound Described by a CCompoundEventSegment object that has had other event segments (both simple and compound) inserted into it.

Traditional A single object of type CTraditionalEventSegment can be incorporated in your readout. Incorporating "traditional" readout software describes how to use this mechanism to incorporate legacy readout software. It is also possible to put the single tradtional readout segement into a compound readout segement and in this way merge it with more modern readout software.

The physical structure of an event is essentially up to the requirements of an experiment. The overall structure of an event buffer is described in Event Data Buffers We recommend that you structure your physical readout in documented packets. The examples in this section will show how to do this, however complete information about documented packets and what they give you is in Documenting event segment packet types

Let's now look at how to specify what is read out. To create a simple readout, you will need to:

• Create a class that inherits from CEventSegment, call it MyEventSegment
• Fill in the the Initialize, Clear and Read member functions of this new class to initialize, clear and read the devices you want to read.
• In MyExperiment.cpp, locate the implementation of SetupReadout and the comment:

  		// Insert your code below this comment.
  		

  Add the line:

  		rExperiment.AddEventSegment(new MyEventSegment);
  		

• Compile your readout as described in Compiling your readout software.

To use Compound Event segments:

• Create several classes that inherit from CEventSegment for example Myseg1, Myseg2.
• Fill in the Initialize, Clear and Read member functions for all of your segments.
• In MyExperiment.cpp, locate the implementation of SetupReadout and the comment:

  	    // Insert your code below this comment.
  	    

  Add the lines:

  	    CCompoundEventSegment* p = new CCompoundEventSegment;
  	    p->AddSegment(new Myseg1);
  	    p->AddSegment(new Myseg2);
  	    rExperiment.AddEventSegment(p);
  	    

• Compile your readout as described in Compiling your readout software.

Note that you may also use compound event segments to build up a hierarchical organization of the readout system. To do this, simply create compound event objects and embed them in other compound event objects.

How to structure your readout