Function Block Properties Dialog Box - General Configuration Tab Overview (MMC)

The Modular Multivariable Control (MMC) instruction controls two process variables (PV) to their setpoints (SP) using up to three control variables. The MMC instruction calculates the control variables (CV1, CV2, and CV3) in the auto mode based on the PV1 -SP1, PV2 - SP2 deviation, internal model, and tuning.
Use the
General Configuration
 tab of the
Function Block Properties
 dialog box to set the values for the parameters of the selected MMC function block.
The following table describes the parameters available on the
General Configuration
tab:
Parameter
Description
Timing
  • Mode
Sets the value of the
TimingMode
 parameter. Supports the following options:
Periodic
 = 0 (default)
Oversampling
= 1
Real Time
 = 2
  • Oversample DeltaSymbolt
Sets the value of the
Oversample
DeltaSymbol
t
 parameter.
This field is only enabled if you chose the
Oversampling
 option for the
TimingMode
 parameter.
Valid values are in the range of 0 to the maximum of the TON_Timer elapsed time (4194.303 sec.)
The default value is 0.
  • RTS Period
Sets the value of the
RTSTime
 parameter.
This field is only enabled if you chose the
Real Time
 option for the
TimingMode
 parameter.
Valid values are in the range of 1...32767 (1 count = 1 millisecond).
Control Variables
  • Override Value
Enter the control variable override value for CV1, CV2, and CV3 in the range of 0.0...100.0.
The default value is 0.0.
Set this value in Override mode.
These values should correspond to a safe state output of the MMC loop.
  • Target Value
Enter the target value for controller output 1, 2, and 3 in the range of 0.0...100.0.
The default value is 0.0.
  • PV1 Deviation Action Priority
Choose the first CV to act to compensate for PV1-SP1 deviation.
The valid values include:
  • CV1
  • CV2
  • CV3
PV1 Deviation Action Priority First, Second, and Third are mutually exclusive.
  • PV2 Deviation Action Priority
Choose the second CV to act to compensate for PV2-SP2 deviation.
The valid values include:
  • CV1
  • CV2
  • CV3
PV2 Deviation Action Priority First, Second, and Third are mutually exclusive.
  • Drive to Target
Choose the CV to be driven to its target value.
The valid values include:
  • CV1
  • CV2
  • CV3
  • Target Response Time Constant
Enter a value in the range of 0.0 to a maximum positive floating value that determines the speed with which the controller outputs approach the target values.
The default value is 0.0.
  • Program Control Value Reset
Select this check box to reset the program control values.
  • Manual Mode after Initialization
When this check box is selected, the appropriate CV1, CV2, or CV3 is placed in the Manual mode when CV1(2)(3)Initializing is set to TRUE unless the current mode is Override or Hand.
When the check box is not selected, the CV1, CV2, or CV3 mode does not change.
PV Tracking
Select this check box to enable the SP to track the PV.
This control is ignored in Auto mode.
Status
Displays status information for blocks containing status bits. If none of the status bits are set, an
OK
 message appears in this field. Otherwise, a list of the status bits that are set appears here. This list is comprised of the parameter names associated with the status bits, and typically explain which parameters were configured with invalid values.
Execution Order
Displays the block's execution number if the routine is in a verified state. If the routine is not yet verified, a
Routine not verified
 message appears. Note that this item is read-only.
Never display description in a routine
Select this check box if you do not want the description to display in the routine.
OK
Click this button to add the selected item in the instruction list to the routine and close the Fun
ction Block Properties
 dialog box.
Cancel
Click this button to cancel any edits you have made and close the
Function Block Properties
 dialog box.
Apply
Click this button to accept your changes and continue editing in the
Function Block Properties
 dialog box.
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