Yokogawa DR240 - Manual (Page 32)

Functions
2-11 IM DR231-01E
2
Partially Expanded Recording
When carrying out trend recording, partially expanded recording enables you to compress a part
of the recording span in order to examine the expanded (other) part of the span in more detail. The
left boundary of the recording span being 0%, and the right boundary of the recording span being
100%, a segment of the recording span can be compressed. The following example shows a
situation where 25% of the recording span has been compressed. The points A, B, C, D, E and F
before compression correspond to the points A’, B’, C’, D’, E’ and F’ in the figure after
compression. The 25% left of the boundary shows –6 to 0V, whereas the 75% right of the
boundary shows 0 to 6V.
6 (V)
0 50 100
–6 –5 –4 –3 –2 –1 0 1 2 3 4 5
Measurement value
(Recording span)
% of full recording
span
Recording
span
Recording
span
A
B
C D
E
F
0
6 (V)
0 25 100
–6 –5 –4 –3 –2 –1
Measurement value
(Recording span)
% of full recording
span
A’
B’
C’
E’
F’
0 1 2 3 4 5
D’
(% of compression:RATE)
(% of compression:RATE)
•Before compressing
•After compressing 25% of recording span
Bounda value
Chart direction
Chart direction
Interpolation Function
When carrying out trend recording and a measurement value differs greatly from the previous
one, the track of the recording changes stepwise in the dot printing. In cases like this,
interpolation will be carried out on the horizontal line to connect the two divergent trend tracks.
When the horizontal lines of several channels are to be recorded on exactly the same location,
only the recording color with the higher priority will be used.
The priority of recording colors is black > purple > red-purple > navy blue > red > blue > brown
> green > orange > yellowish green, which means that black has the highest priority. In the figure
below a recording example is given of a horizontal line in the colors black, red and yellowish
green. In the area where red and yellowish green overlap (labeled as a), only red dots will be
recorded, and in the area where black, red and yellowish green overlap (labeled as b), only black
dots will be recorded.
However, at the locations where the recordings diverge after connecting a horizontal line, all
recording colors will be recorded.
a b
Red Yellowish
green
Black
Chart direction
2.3 Recording Functions