Rockwell Automation 1404-M4_M5_M6_M8 Powermonitor 3000 User Manual, Firmware rev. 3.0 or LATER - Manual (Page 150)

150 Publication 1404-UM001F-EN-P - November 2009
Chapter 7 Data Logging
Parameters per Record Formula
If your application requires a certain number of records or time to
preserve logged information, this formula returns the number of
parameters per record allowed.
Where:
CEIL (x) = the smallest integer greater than x.
Examples
Example 1: You want to log kWh every 15 minutes and you want to
know how many records the log contains and how long a time that
covers. The
Trend Log Depth Formula applies to this example.
Fill and hold mode allows logging the most records. Logging only 1
parameter per record, the formula results in a total of 17,640 records
after rounding down. Logging every 15 minutes, this log configuration
will log 6.1 months of kW data.
EXAMPLE
For example, CEIL (1914.28) = 1915.
Suppose D = 13400 and F = 0, we will get
Suppose D = 13500 and F = 0, we will get
P INT
16384
CEIL
D
7 F –
------------
⎝ ⎠
⎛ ⎞
-------------------------------- 5.5 –
⎝ ⎠
⎜ ⎟
⎜ ⎟
⎜ ⎟
⎛ ⎞
=
P INT
16384
CEIL 1914.28 ( )
-------------------------------------- 5.5 –
⎝ ⎠
⎛ ⎞
INT 3.05 ( ) 3 = = =
P INT
16384
CEIL 1928.57 ( )
-------------------------------------- 5.5 –
⎝ ⎠
⎛ ⎞
INT 2.99 ( ) 2 = = =