YOKOGAWA Admag TI Series User Manual page 84

*1: From the table below, select the noise filter (rate limit value and dead time).
Selection
F
OUNDATION
Display
Fieldbus
Manual Manual
Level 1 Level 1
Level 2 Level 2
Level 3 Level 3
NOTE
If either the rate limit value or the dead time is specified, the noise filter is set to "Manual".
NOTE
Determining the rate limit value and dead time
The Rage limit value:
Determine the level which should be cut the output
fluctuation. For example, if its level is 2%, the noise of 2%
or larger would be cut as shown in the following figure.
2%
2%
NOTE
For the rate limit function, the dead time is set to "0" at shipment from the manufacturing factory.
Be sure to set the dead time when the rate limit function is used.
Signal processing for rate limit function
The product calculates to set the specific rate limit value to the primary delay response value of
the previously sampled flow rate value. If the flow rate value sampled at this time exceeds the
rate limit value above, its high or low limit is set to the flow rate value at this time. Furthermore,
if the sampling count occurs within the dead time while the signal over the high/low limit is in the
same direction, this signal is judged to be a flow rate signal.
Rate limit value
The value is specified in the
parameter "Rate limit".
0.5%
1.0%
5.0%
The Dead time (T
Determine the value depending on the width of the output
fluctuation. Choose the larger value when the noise which is
over the dead time as shown in the following figure.
T
0
<5. Functions>
Dead time
The value is specified in the
parameter "Dead time".
0.5s
1.0s
3.0s
):
0
T
0
F0420.ai
83
IM 01E21A02-03EN