100/180 mm PAPERLESS GRAPHIC RECORDER: USER GUIDE
User Guide
Page 69
HA028910
Issue 13 Sep 16
RECORDING ENABLE
This tick box allows the logging of this group’s data to the fl ash memory to be enabled/disabled. When
disabled:
a
The recording speed/interval fi elds are not editable, and Trend History duration is set to zero.
b Display trends are present on the chart, but are not preserved when changing ‘Views’.
c
It is not possible to enter trace history if ‘Recording Enable’ is not selected.
Notes
1 A blue line is drawn across the chart, when recording is re-enabled to indicate a time change in
the trace.
2 If a ‘Recording enable’ job (
section 4.7.10
) is set to act on a particular group, then the group will
be recorded only whilst the job is active, and only if Recording is enabled for the group.
RECORDING SPEED/RECORDING INTERVAL
If recording is enabled, these fi elds are as for trend speed/interval but defi ne the rate at which data is
saved to Flash memory. This value also affects how much trace history appears per screen in trend his-
tory mode (
section 3.4
). If recording is not enabled, these fi elds are ‘greyed’ and not editable.
If A/B switching is enabled, a second Recording Speed /Interval value can be entered. Recording Speed/
Interval ‘A’ is used during normal operation. Recording Speed/Interval ‘B’ is switched to by job action, as
described in
section 4.7
.
Note: With large numbers of points confi gured in one or more groups, the total amount of data
generated per iteration may exceed the amount that can be written to the internal FLASH memory
in the time available. Such a situation may also arise if many messages are being generated. The
recorder responds by reducing the recording speed, and a message ‘Recording failed - internal
overfl ow. Slowing recording interval of fastest group(s)’ appears, to draw the user’s attention to
the situation.
TREND HISTORY DURATION
Gives an estimated time to fi ll the group’s trend history area of the Flash memory. The calculation is
based on the archive rate, the compression ratio, the fl ash size and on the exact nature of the data. (Rap-
idly changing values use more space than static/slowly changing values.) If A/B switching is enabled the
calculation is based on Recording Speed/Interval ‘A’.
Changing the contents of one group may affect the Trend History Duration of other groups. This hap-
pens because the recorder attempts to store, as nearly as possible, the same amount of history for all
groups, regardless of how many points there are in the groups.
For ‘empty’ groups, or if Recording is not enabled for a group, the Trend History Duration is displayed as
‘0’ Days.
ARCHIVE TO MEDIA ENABLE/ARCHIVE VIA FTP ENABLE
If recording is enabled, these tick boxes allow the archiving of this group’s data to removable mass stor-
age media and/or to a remote host (FTP) to be enabled or disabled. If recording is disabled, these fi elds
cannot be edited.
Note: When recording to fl oppy disk drives (via a USB port), it is recommended that only one
group be set up with ‘Archive to media’ enabled. This is because history fi les are typically 400kB
in size and this limits the number of fi les which can be saved to a 1.4MB fl oppy disk, to three. If
more than one group is set up to archive, and if ‘Overwrite’ strategy is selected, then it is likely that
all the data for one or more of the groups will be lost. No warning is given.
