Specifications

sigmadue - IEC 61131-3 Function Block Library
92
Manual Access Parameters
The FB provides all the functionalities the operator needs to interact with the loop.
The loop is controlled by one PID, connected internally to an AutoManual block. By a
set of digital inputs the function block provides auto/manual/track/aux operating mode
as listed above, ordered according to their priority level.
Tr k
DTRK
AutoMan DAM
Aux DAUX
Depending on these digital inputs, the functionality of the module changes as follows:
• If none of these digital signals are active, the module does not alter the
control output signal (from the PID module).
•If
DTRK (Tracking) is active, the output OUT assumes the value of the
analog input
TRK .
•If the
DAM input is active (and DTRK is inactive) the output OUT assumes
the value of the analog input AM_VAL.
•If
DAUX (Aux) is active (and both DAM and DTRK are inactive), the output
OUT assumes the value of the analog input AUX .
Note: Please note that the OUT limit inputs ( OUTLO , OUTHI ) do not affect the output
values coming from the Manual Access (i.e.
DAM input TRUE ).
Inputs M_RES and FFWD are used to set a fixed offset to add to the PID calculation.
The system does not add boot terms but select FFWD if it is different from zero,
elsewhere the system add M_RES.
Automatic Tune
This function block is able to perform tuning calculation. The FB select the EZ tune
method if ATB is greater than zero, elsewhere it use the FUZZY method. To
understand how these methods work refers to the documentation of the function
blocks S2_EZ_TUNE and S2_TFUZZY.
AM_VAL 0.0
DAUX FALSE
AUX 0.0
PVLO 0.0
PVHI 100.0
OUTLO 0.0
OUTHI 100.0
Output Default Value
OUT 0.0
TPB 0.0
TTI 0.0
TTD 0.0
AT_STS FALSE
AT_FAIL FALSE
Input Default Value