Dr 23 - Selection For Type Of Controller - Siemens SIWAREX FTA Device Manual

Weighing Functions

5.16.29 DR 23 - Selection for type of controller

Two controllers are integrated in SIWAREX FTA: A proportional controller for
correcting the definition for the trailing weight and a fine signal time controller for
ensuring the defined duration for the fine signal.
It is also possible to run both controllers at the same time.
5.16.30 DR 23 - Control factor Proportional controller
The proportional controller sets the definition for the trailing weight to adjust it to
the actual trailing amounts.
The determined deviation of the weighing net value from the weighing set value is
multiplied with the defined control factor (Control factor Proportional controller) and
is used for the next filling as a correction set amount.
The trailing weight for the following weighing procedures is calculated according to
the following formula:
G = G
(n+1) n
G
(n+1)
G
n
S
A
C
n
n+1
5.16.31 DR 23 - Maximum one-time correction with the proportional controller
The proportional controller sets the definition for the trailing weight to adjust it to
the actual trailing amounts. By defining the maximum correction value, the one-
time change can be limited by the controller. This limits runaway values to the
maximum correction value.
The trailing weight is modified by the value
(S – A)n • C/100%
If the calculation results in a larger value than the maximum correction value, only
the maximum correction value is used for the correction of the trailing weight.
Therefore, the formula for calculating the trailing weight is now:
G = G
(n+1) n
5-106
+ (A – S)n • C/100%
Trailing weight for the next weighing procedure
Trailing weight for the last weighing procedure
Set weight
Net weight for the last weighing procedure
Control factor for proportional controller in %
Current weighing procedure
Following weighing
+ maximum correction value
SIWAREX FTA