5-6
Example:
Write the value 0 (0000H) to the Window Index Historical Log 1, Register 38145.
15. Read Window from the beginning up to (but not including) the Ending Offset.
Ending Offset = First Register of Window + (Ending Window Offset/2).
Example: (Index = 31).
38273 +40/2 = 38293.
Read from 38273 up to (but not including) 38293; therefore, read 38273 – 38292.
16. Un-pause the log by writing FFFFH to the Window Index.
Example:
Write the value FFFFH to the Window Index for Historical Log 1, Register 38145.
55..11..33::
DDoowwnnllooaaddiinngg
RReeccoorrddss
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EExxaammpplleess
QThe following steps detail the process for downloading records from a log, using values from an
Historical Log 1 as an example.
1. Read the EPM Programmable Settings Block (Registers 45057–53248).
2. Pause the log by writing an initial, non-FFFFH value to the Log Window Index Register.
Example: Write 0000H to the Window Index for Historical Log 1, Register 38145.
3. Read and store the Log Header information.
Example: Historical Log 1 Snapshot Header
Address Description Example Value
36865–36866 Historical Log 1 Snapshot Memory Size 1851392
36867 Historical Log 1 Snapshot Record Size 64
36868 Historical Log 1 Snapshot First Index 501
36869 Historical Log 1 Snapshot Last Index 500
36870–36873 Historical Log 1 Snapshot First Timestamp 7/10/99 12:32:00.000
36874–36877 Historical Log 1 Snapshot Last Timestamp 7/30/99 14:40:00.000
36878–36881 Historical Log 1 Snapshot Valid Bitmap FFFC 0000
36882 Historical Log 1 Snapshot Max Records 28928
4. Determine the starting Window Index and starting Window Offset using these formulas:
Starting Window Index = Int([Record Size x First Index]/128).
Starting Window Offset = (Record Size x First Index) % 128.
Example:
Starting Window Index: Int(64 x 501/128) = Int (250.5) = 250.
Starting Window offset: (64 x 501) % 128 = 64.
5. Determine the largest Window Index and the largest Window Offset using these formulas:
Largest Window Index = Int([Record Size x Max Records]/128).