GE EPM 9650/9800 manual Downloading Records with Examples

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.

5.1.3: Downloading Records with Examples

The 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).

5-6