User Manual

Chapter 8 System Parameters and Comm ands
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8.3.1 General Structure of an Event Record
Th ere ar e 2 m ain ty pes of Ev ent reco rds: Sh o rt E v ent Reco rd an d L on g
Event Record. In DataSealLib, both types are represented by the SealEvent
class, but the Short Event Record does not use all the members. T he
following SealEve nt class members are used both in Short Events and in
Long Event records:
 Number – The sequential number of the Event record.
 Code – The code (type) of the Event record. T he
HGTEventCodeEnum enumeration contains the constants for these
codes.
 DateTime – T he date & time (in UTC) when the event occurred.
 Se alStamp – The value of the Se al Stamp parameter when the event
occurred.
 CRC – The Cyclic Redundancy Check code that ensures the validity of
the first part of the record.
The following SealEve nt class members are used only in the Long Event
records:
 CodeEx – The code of the extension of the Event record. This is
always the same as Code + 80h.
 Reader ID – The ID of the device that caused the Event (for example,
in a Set operation). Note that this is not necessarily an ID of a
DataReader – it could also be the ID of a DataTerminal, DataPort or
any other kind of device that could cause the Event.
Note
: If DataSealLib recognizes the Reader ID as a DataReader that it
knows it returns the Rea de r object instead of the Reader ID itself.
 Se alStamp2 – 2 Additional bytes that contain data specific to the type
of Event. Most Event types does not use this field at all.