Yokogawa JUXTA VJX7 - Manual (Page 5)

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9.5 VJX7-E (First-order Lead Computation)
This computing unit provides a first-order lead computation on in-
put (X) with a time constant (T) and outputs the result (output-
1=Y1, output-2=Y2). Set the time constant (T) at % value in H01:
CONST. The value of 0 to 100% corresponds to that of 0 to 100
seconds.
● Setting range of time constant:
0 to 799.0 seconds; minimum unit is 0.1 second.
● Accuracy of time constant setting:
(
±
5.0% of set value)
±
1 second
Y1=Y2= (1+ ) X
TS
1+TS
e.g. 0%
→
50% step input
Input 0%
68.4%
50%
100%
50%
Output 0%
T
9.6 VJX7-F (Velocity Limiter)
This computing unit limit the input (X) velocity at the ascending
velocity limit for a positive change and the descending velocity
limit for a negative change, and outputs the limited value (output-
1=Y1, output-2=Y2). When the input velocity (slope) is no more
than the limit value, the unit outputs the input as is.
Set the ascending velocity limit at % value in H01:CONST, and
the descending velocity limit at % value in H02:CONST. The
value of 0 to 100.0% corresponds to that of 0 to 100.0%/minute.
e.g. 0%
→
100%
→
0% step input
Input 0%
100%
100%
Output 0%
Ascending velocity limit
(%/minute)
Descending velocity limit
(%/minute)
● Setting range of velocity limit value:
0.1% to 699.9%/minute; minimum unit is 0.1%/minute.
Setting the limit at 700%/minute or above does not limit the
input, so the unit simply outputs the input as is (i.e., works as
an open limit function).
● Accuracy of velocity limit setting:
(
±
5.0% of set value)
±
1 %/minute
9.7 VJX7-G (Limiter)
This computing unit serves as an ordinary converter as long as the
input (X) is within the upper and lower limits. When the input ex-
ceeds the limit, the unit outputs the signal that corresponds to the
limit value (output-1=Y1, output-2=Y2).
Set the upper limit at % value in H01:CONST, and the lower limit
at % value in H02:CONST.
● Setting range of upper and lower limit value:
-6.0% to 106.0%; minimum unit is 0.01%.
However, if the setting is made so that the upper limit < lower
limit, the unit outputs the upper limit value.
9.8 VJX7-H (Velocity Computation)
This computing unit calculates the input velocity by subtracting
the input of the last velocity computation (XL) from the present
input (X). The unit then adds a 50% bias to one-half of the ob-
tained velocity and outputs the result (output-1=Y1, output-
2=Y2). The output results is 50% when the input is not changed,
50% or more when the input increases (100% for X-XL 100%),
and 50% or less when the input decreases (0% for X-XL –100%).
When using a first-order lag filter for input (X), set the first-order
lag time constant (T).
Y1=Y2= +50%
X–X
L
2
Set the velocity computation time (L) at % value in H02: CONST.
The value of 0 to 100.0% corresponds to that of 0 to 1000 seconds.
For example, enter “6” to set in H02 when setting 60 seconds.
● Setting range of velocity computation time:
0 to 320,000 seconds (about 3.7 days) with 4 significant digits
Minimum unit is 1 second (however, 0.1 second is possible
for 4 seconds or shorter).
( e.g. 12345% is impossible, 12340% is possible.)
First-order lag time constant (T) is set at % value in H01:
CONST. The value of 0 to 100% corresponds to that of 0 to
100 seconds.
● Setting range of time constant:
0 to 799.0 seconds; minimum unit is 0.1 second.
● Accuracy of moving average and time constant setting:
(
±
5.0% of set value)
±
1 second
9.9 VJX7-J (Linearizer)
This computing unit gives an optional relationship between the in-
put (X) and output (output-1=Y1, ouput-2=Y2) signals using an
optional line-segment function. The line-segment function has 21
breakpoints, which each gives an input-output relationship as a
percentage (%). Set the input (X) at % value in H01:CONST to
H21:CONST, and the output (Y) at % value in H22:CONST to
H42:CONST.
● Breakpoint (21 points) setting conditions:
For input: -6.0 ϹX0 (H01) to X20 (H21)Ϲ106.0%; minimum
unit is 0.01%
X0For output: -6.0
ϹY0 (H22) to Y20 (H42)Ϲ106.0%; minimum
unit is 0.01%
When input
ϹX0 (H01), Y0 (H21) is output.
When input м20 (H22), Y20 (H42) is output.
● Computation accuracy:
±
1 % (when line-segment gain is 1 or less)
9.10 VJX7-K (Ratio Setter)
This computing unit sets the ratio by the following expression.
Y1=Y2=K1
×
(X+A1)+A2
where Y1: Output-1 signal (%)
Y2: Output-2 signal (%)
X: Input signal (%)
K1: Ratio (no unit)
A1, A2: Bias (%)
Set the ratio (K1) in H01:CONST, and the bias (A1) at % value in
H02:CONST, and the bias (A2) at % value in H03:CONST.
● Setting range of ratio:
-320 to 320 with 4 significant digits; minimum unit is
0.00001.
● Setting range of bias:
-32,000% to 32,000% with 4 significant digits; minimum unit
is 0.001%.
● Computation accuracy:
±
1 % (when K1=1, A1=A2=0%)
NOTE
Set the ratio or bias not to exceed
±
9
×
10 20 % during the com-
putation. The computation result of ratio or bias is 4 signifi-
cant digits.