6. FUNCTION AND DATA SETTINGS
IM 1E7B0-02E
6-15
6.3.14 Procedure of Selecting Special Application Items
•
Only the special apprication (“n” items) shipped being unpublished.
In case the “n” items should be used, it can be set “55” in parameter No. “L2”.
Display
Description
Code
Content
00
01
Accessible up to L parameters
Accessible up to n parameters
It is possible to open up to item n when "55" is entered in parameter number
"L2".
Default : 00
6.3.15 Rate Limit
•
This function is used to remove noise that cannot be removed by increasing the
damping time constant.
•
In case unexpected noise from step signal or slurry is entered, a basis is set to
recognize that signal is flow rate or noise.
The recoginition depends on rate limit value (upper and lower limit) and dead time
(sampling time).
•
Determination of rate limit value and dead time.
Rate limit value:
Determine the level to reduce output
fluctuation.
For example, reducing 2% or more
fluctuation by setting as 2% to reduce.
2%
2%
T
0
T
0
Dead time
T
0
:
Please determine the dead time
depending on output fluctuation width.
In case of noise of which is longer
than the dead time, please set the
dead time longer.
•
Signal processing procedures:
The function sets a certain upper and lower limit (rate limit value) for first order
delay response values of flow rate data obtained in a previous sampling. If currently
sampled flow rate data exceeds or goes below the limit is regarded as current flow
rate value. Signals whose protruding portions show the same trends during a certain
number of sampling times (dead time)are identified as flow rate signals.
Example 1: Step Input
1%
10%
Step Signal
Flow rate value
after rate limiting
Flow rate value after
damping
(3)
(1)
(2)
9
18
(4)
63.2%
Input: 0 to 10%
Damping time constant: 3 sec.
Dead time: 3 sec.
Rate limit value: 1%
Dead time: 3 sec.
Sampling times
