ProSoft Technology PTQ-AFC - Manual (Page 115)

PTQ-AFC ♦ Modicon Quantum Platform Quick Start
Liquid and Gas Flow Computer for Hydrocarbon Products User Manual
ProSoft Technology, Inc. Page 115 of 259
June 23, 2011
6.12.2 Event Log structures
The Event Log header contains housekeeping information for maintaining the
Log. Its layout is:
Address Description
40000
Number of records maximum ( == 1999 )
40001
Next new record position ( 0 thru maximum-1 )
40002 Next new event number ( 0 thru 65535, wrapping to 0 )
40003 Oldest event number on file
40004 Oldest event number on file not yet downloaded
40005-40007 [reserved]
Each event record is an 8-register quantity laid out as four 32-bit items (big-
endian):
Registers Contents
0 to 1 Event Id Tag (page 116)
2 to 3 Timestamp of event
In our standard "packed bit-field" format.
4 to 5 Old item value
For a Datum Point event, format depends on the "datum type" field of the
Event Id Tag.
6 to 7 New item value
For a Datum Point event, format depends on the "datum type" field of the
Event Id Tag.
Each value is right-justified in its field and sign-extended if necessary.