Function Block Properties dialog box - EU Scaling tab (IMC)
The Internal Model Control (IMC) instruction controls a single process variable by manipulating a single control-variable output. This function block performs an algorithm where the actual error signal is compared against that of an internal first-order lag plus deadtime model of the process. The IMC function block calculates the control variable output (CV) in the Auto mode based on the PV deviation from the set point (SP), internal model, and tuning.
Use the
EU Scaling
tab to set the Engineering Unit (EU) scaling values for the selected IMC function block.The following table describes the parameters available on the
EU Scaling
tab:Parameter | Description |
Process Variables | |
| Enter the maximum scaled value for PV, which is the value of PV and SP that corresponds to 100 percent span of the Process Variable. Valid values are in the range of PVEUMin < PVEUMAX  maximum positive floating point value. The default value is 100.0 |
| Enter the minimum scaled value for PV, which is the value of PV and SP that corresponds to 0 percent span of the Process Variable. Valid values are in the range of maximum negative floating point value PVEUMin < PVEUMax. The default value is 0.0 |
Control Variables | |
| Enter the maximum value for CVEU, which is the value of CVEU that corresponds to 100 percent CV. |
| Enter the minimum value for CVEU, which is the value of CVEU that corresponds to 0 percent CV. |
Status | Displays read-only 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 Number | 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 displays. 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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