Rockwell Automation 1404-M4_M5_M6_M8 Powermonitor 3000 User Manual, Firmware rev. 3.0 or LATER - Manual (Page 151)

Publication 1404-UM001F-EN-P - November 2009 151
Data Logging Chapter 7
Example 2: Another user wants to log several parameters every
5 minutes indefinitely, retrieving the records within one week after the
end of each month. He saves the retrieved data and creates trend
graphs on his PC. The question is how many parameters may be
monitored. The
Parameters per Record Formula applies to this
example.
The total log depth of 10,944 is based on the log duration and interval:
(31 days per month + 7 days) * (24 hours per day) * (60 minutes per
hour) / 5 minute logging interval. Overwrite mode (F = 1) allows you
to read the log any time without losing any data.
In this example, P, the number of parameters that may be recorded,
is 3.
From this example, you can see that the trend log can log 3
parameters every 5 minutes in a 38-day sliding window.
Setting up the Trend Log
You configure the Trend Log by performing a table write to the Trend
Log Configuration/Read-back Record Select table with the desired
configuration settings. This read/write data table contains 26 integer
elements including the following:
•
Password: Required to configure logging, you may use -1 for
read-back selection
•
DeviceNet unique write identifier
•
Read-back mode: See below; must be a valid entry even if
read-back is not being selected at this time
•
Logging interval: Interval in seconds (1…3600). 0 disables
logging but does not disable setpoint-triggered logging; -1
synchronizes logging with demand interval.
•
Logging mode: 0 selects overwrite mode; 1 selects fill and hold.
•
Clear log command: 0 takes no action; 1 clears the trend log.
•
Parameter selections: You may select up to 16 parameters from
the list in the
Parameters for Trend Log and Configurable Table
table to be logged. An entry of 0 selects no parameter; only
parameters preceding the first 0 in the table is logged.
•
Reserved elements: Must be 0
•
Total records logged: These read-only elements are ignored
during a write