Honeywell Minitrend QX, User Manual

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43-TV-25-30 Iss.6 GLO Aug 07 UK 193
Chart/Logged data Slider
An adjustable slider shows how much memory is allocated to Chart data and how much
memory is allocated to Logged data. The user can adjust the slider which will display how
long it will take to fill the memory, at the current chart speed, before the data will start to be
recycled.
See “Storage Bias” on page 116
How Replay works
There are three separate “queues” of data, represented by the three different chart speeds.
As you zoom in and out it switches between these different “queues”.
These “queues” are not all the same length, so for example:
• The fast speed may be at 600mm/hr which means to cover 24 hours takes approx.
30Mbytes for 8 pens.
• The medium speed may be at 20mm/hr which means that to cover 24 hours takes 1Mbyte
(1/30 of fast).
• The Slow speed may be at 1mm/hr which means that to cover 24 hours takes 50Kbyte
(1/20 of Medium).
The result of this is that the slow speed will tend to give you much more elapsed time history,
but at a lower time resolution, here is a representation of what this could look like.
The lines represent absolute time coverage. So if you go right back to the earliest time on
the slowest chart (shown by ‘!’ in this example), you cannot zoom in any more as the medium
speed coverage does not go back that far.
Zooming Capabilities
The example in Figure 6.4 on page 194, shows 10 different replay screens covering the
full zoom in/zoom out capabilities. When the screen is switched to replay the chart speed is
set to Fast (600mm/hr) and the replay screen displays a 4 hour chart. The replay chart can
be zoomed out two more times to 10 hours, then to 12 hours. It can be zoomed in from 4
hours to 2hrs, 1hr, 1hr (with bigger divisions), 20 mins, 10 mins, 5 mins, 2 mins and 1 min.
The Medium chart speed (20mm/hr and the Slow chart speed (5mm/hr) are also shown in
the example.
Data
2 week 4 weeks 6 weeks 8 weeks 12 weeks
Fast speed
Medium speed
! Slow speed