Programmatic Logic

All unpacking is performed by a parser class unique to the data type being unpacked (GRIF-16 fragment, GRIF-16 scalar, PPG or GRIF-4G fragment). Simultaneously, the parser checks for inconsistencies in the data, via the following pattern

1. Each parser contains an assessComposition method, which checks that a valid number of words appear in a valid order in the event; any problems are recorded in the dataStore in an array of error messages.

2. For each word type, the parser contains a function to unpack that word and raise warnings about problems aparent in that word.

3. Finally, each parser contains a last-pass function postProcessingFlags to check for any inconsistencies apparent after unpacking is complete.

List of Sanity Checks

GRIF-16 Fragments

Event-Level

• must have at least 10 words
• first word must start with 0x8
• second word must start with 0xD
• third word must start with 00
• fourth word must start with 0
• type V must start with 0x9
• type VI must start with 0xA
• type VII must start with 0xB
• allow a run of type VIIa words
• type VIII must start with 0
• type IX must start with 0
• type X must start with 0xE
• type X word must be last word in event

Word-Level

• Type I
• Must have valid module code
• Number of words reported in header must match actual number of words (excluding type VIIa)
• Must have valid detector code
• Type III
• Make sure there are no type VIIa words if the waveform bit is unset, or the converse.
• Type VI & IX
• Timestamp low bits and CFD time should be within 10k units of each other.

GRIF-4G Fragments

Analogous to GRIF-16 Fragments.

PPG

Event-Level

• must have 7 words
• each word must have the correct type flag, in order

Word-Level

• Type I
• Must have valid module code
• Must have valid detector code

Scalers

Event-Level

• must have at least 5 words
• each word must have the correct type flag, in order

Word-Level

• Type I
• Must have valid module code