EFA.h File Reference

Defines the functions to a header common to all event-based analysis. More...

#include <EFC/EFA_def.h>

Typedefs
typedef struct _EFA	EFA
typedef struct _EFA_hdr	EFA_hdr
	Typedef for _EFA_hdr.
typedef struct _EDS_cfgInfo	EDS_cfgInfo
Functions
int	EFA_construct (EFA *efa, void *pool, int enable, const EFA_services *services, void *ctx, unsigned int size, unsigned int postCnt, unsigned int recCnt)
int	EFA_flush (EFA *efa, int reason)
int	EFA_notify (EFA *efa, int mode, const EDS_cfgInfo *cfg)
int	EFA_resultSizeof (const EFA *efa)
int	EFA_sizeof (int result_size, int result_cnt)
int	EFA_enable (EFA *efa, int enable)
int	EFA_start (EFA *efa, int reason, int run_id, int startTime, int mode)
unsigned int	EFA_hdrCompose (EFA_hdr *hdr, unsigned int relative, unsigned long long seq, unsigned int gemClock, unsigned int gemStrobe)

---

Detailed Description

Defines the functions to a header common to all event-based analysis.

Author:

JJRussell - russell@slac.stanford.edu

   CVS $Id: EFA.h,v 1.2 2011/03/27 04:55:29 russell Exp $

---

Typedef Documentation

EFA_hdr

Typedef for _EFA_hdr.

This structure is used to uniquely identify an event in both time and sequence. As such, it contains enough information to calculate the absolute time of the event. To do this one needs the GEM clock frequency which can be got in an assumption free fashion by capturing the GEM clock value on two successive timetone/1PPS hacks. The difference in the GPS timetone messages gives one the elapsed seconds and the difference in the GEM clock register values gives how many clock ticks have passed during this period.

The event sequence number is merely the GEM sequence number extended by watching how many times this sequence counter overflows. (Overflow is defined as going from a given value to a lower value.) While this is an easy enough value to compute, the writer is encouraged to use the value from EDS_fwIxb. This will ensure agreement when readers examine data from different statistics blocks.

Note:

This structure exists so that it may passed to a convenience routine (likley within THS) for easy filling.