Chapter 3. Logging Data
70
DigitalFlow™ DF868 Multipurpose Ultrasonic Liquid Flowmeter Programming Manual (2-Channel)
3.2.9 Checking the Memory
Use the
MEM
submenu to verify that the available log memory is sufficient for the desired log. If the expected amount
of logged data will exceed the remaining memory capacity, the Model DF868 suggests that some old logs be cleared
to make room for the new log.
Press the appropriate side of the
[SCREEN]
key to activate the desired pane of the display screen, and complete the
following steps:
1.
To access the
Log Menu
, press
[LOG]
.
a.
If you have activated the security feature (see Chapter 1,
Programming Site Data
, page 50 for details), enter the
assigned password and press
[ENT]
.
2.
Press
[F2]
=
MEM
.
3.
After noting the information, press
[ENT]
to return to the main
Log Menu
screen.
The
MEM
screen lists the number of remaining unused memory pages out of the total number of 120 available pages.
Also, the number of pages expected to be used by all currently programmed logs is given. If the number of pending
pages exceeds the number of free pages, additional memory may be made available by clearing some old logs (see
Chapter 5,
Clearing Data
).
If it is undesirable to delete old logs to free up additional memory, the number of pages pending may be reduced by
altering the parameters of one or more of the currently active logs. For example, either increasing the time increment
or decreasing the total logging time will reduce the memory requirements for a log file. Use the following equations
to calculate the number of pages used by a log:
Consider a log that is set to run for 24 hours with a time increment of 3 minutes. From Equation 1, the number of
records = (24 x 60)/3 = 480 records. Then, from Equation 2, the number of pages = 480/120 = 4 pages. Thus, at least
four pages of memory must be available for this log to run to completion. Notice that increasing the time increment
to 6 minutes or decreasing the length of the log to 12 hours would reduce the memory requirement to only 2 pages.
number of records
length of log
time increment
---------------------------
=
number of pages
number of records
120
---------------------------------
=