West Control Solutions KS98-1 - Manual (Page 168)

Examples:
Trend recording with 2 curves
Although distinction of different curves is not possible,
display of two values on a trend page may be purposeful
(e.g. controller and process value, or one value and zero,
in order to have a curve).
In the example, a clock triggering switch-over between
the values together with the SELV1 is generated by me-
ans of a pulse.
In the example, a TIME1 can be used to generate a clock
for switching over between values with SELV1.
E.g. for making a record in VTREND at intervals of a se-
cond, unit is s and sample is 1.
In order for the TIME1 to change between 0 and 1 once per
second, T1 and T2 must be set to 0,9 s. One cycle (0.1s) is
lost for detection of the own output change).
In the following example, a pulse is used to create
a clock which generates switchover between valu-
es with SELV1.
For making a record at intervals of a second
e.g. in VTREND,
Unit is set to s and
Sample is set to 1.
Settings:
Unit = s and S
ample =1 = 1/s = 3600/h
x0=0, x100 and pulse/h to 3600, 1/2 sample interval = 1800 must be applied to pulse input x1.
Cascading
Trend or data recording with any number of values can be realized by cascading VTREND function blocks.
Limiting refers only to the number of available block numbers and to the calculation time. The data sequence is de -
pendent of VTREND function block wiring. In wiring direction the block numbers must be ascending.
9499-040-82711 Visualization
VTREND ( trend display(No. 99) ) III-168
TIME1
z1 not
z
1
T 1
T 2
d1
100 ts=11
Takt
Weff
X
Y
XW
W
Yout1
Yout2
Bl-no
we
/w
i
pi
/p
or
u
n
os
ta
b
oe
rr
xw
su
p
p
gr
of
f
rs
ta
rt
o_hi
de
opl
oc
k
SELV1
Y 1
X 1
X 2
X 3
X 4 d1 d2
102 ts=11 VTREND
X-125
Bl-no
ready
X 1
hi
de
di
s
abl
re
se
t
sa
m
p
le
103 ts=11
VTREND
X-125
Bl-no
ready
X 1
hi
de
di
s
abl
re
se
t
sa
m
p
le
100 ts=11
VTREND
X-125
Bl-no
ready
X 1
hi
de
di
s
abl
re
se
t
sa
m
p
le
101 ts=11
VTREND
X-125
Bl-no
ready
X 1
hi
de
di
s
abl
re
se
t
sa
m
p
le
109 ts=11
Values x ... x-100 Value x-101 ... x-200
the oldest
100 values saved
Fig. 26 Example of trend- /datarecording with n values