FragmentHeader v4¶
This document describes the format of the FragmentHeader
struct, version 4. It should not be updated, but rather kept as a historic record of the data format for this version.
FragmentHeader Description¶
Version 4 of the FragmentHeader
consists of 18 32-bit words:
-
Marker (0x11112222)
-
Version (0x00000004)
-
Size in bytes, including header and Fragment payload (upper 32 bits)
-
Size in bytes, including header and Fragment payload (lower 32 bits)
-
Trigger number (upper 32 bits)
-
Trigger number (lower 32 bits)
-
Trigger timestamp (upper 32 bits)
-
Trigger timestamp (lower 32 bits)
-
Data window begin (upper 32 bits)
-
Data window begin (lower 32 bits)
-
Data window end (upper 32 bits)
-
Data window end (lower 32 bits)
-
Run Number
-
Error bits
-
Fragment Type
-
Sequence Number (upper 16 bits) / Padding (lower 16 bits)
-
SourceID version 2 Version (upper 16 bits) / Subsystem (lower 16 bits)
-
SourceID version 2 Element ID
C++ code for FragmentHeader¶
using run_number_t = uint32_t;
using trigger_number_t = uint64_t;
using fragment_type_t = uint32_t;
using fragment_size_t = uint64_t;
using timestamp_t = uint64_t;
using sequence_number_t = uint16_t;
struct FragmentHeader
{
static constexpr uint32_t s_fragment_header_marker = 0x11112222;
static constexpr uint32_t s_fragment_header_version = 4;
static constexpr uint32_t s_default_error_bits = 0;
uint32_t fragment_header_marker = s_fragment_header_marker;
uint32_t version = s_fragment_header_version;
fragment_size_t size{ TypeDefaults::s_invalid_fragment_size };
trigger_number_t trigger_number{ TypeDefaults::s_invalid_trigger_number };
timestamp_t trigger_timestamp{ TypeDefaults::s_invalid_timestamp };
timestamp_t window_begin{ TypeDefaults::s_invalid_timestamp };
timestamp_t window_end{ TypeDefaults::s_invalid_timestamp };
run_number_t run_number{ TypeDefaults::s_invalid_run_number };
uint32_t error_bits{ s_default_error_bits };
fragment_type_t fragment_type{ TypeDefaults::s_invalid_fragment_type };
sequence_number_t sequence_number {TypeDefaults::s_invalid_sequence_number };
uint16_t unused {0xFFFF};
SourceID element_id;
};
Fragment Notes¶
A Fragment
is a flat array consisting of a FragmentHeader
and payload data (e.g. data from electronics readout). The format of this data should be able to be inferred from the fragment_type
field of the FragmentHeader
.
Last git commit to the markdown source of this page:
Author: John Freeman
Date: Mon Jul 11 15:35:15 2022 -0500
If you see a problem with the documentation on this page, please file an Issue at https://github.com/DUNE-DAQ/daqdataformats/issues