The DeltaV system is comprised of workstations, controllers and I/O, and the control network. The controllers execute the control strategies for their assigned control modules. Certain workstations also provide the ability to host control modules and execute their associated control strategies. This functionality in the workstation is called the virtual controller. The virtual controller is available on the ProfessionalPLUS and Application Station workstation types where the workstation may be used as another controller; that is, performing the same function as a physical controller by allowing control modules to run on the workstation.
Using the workstation as a virtual controller allows you to keep controller resources available for other control processes. The virtual controller should be used to host supervisory or data acquisition control strategies, where execution of the control strategy is not critical. The Windows operating system running in the workstation is not a real-time operating system like the operating system in the physical controller, and thus the virtual controller should not be used for real-time control. Typical control modules assigned to the virtual controller include control strategies using OPC data values or Bailey Connect interface blocks.
For a workstation acting as a virtual controller, it is not advised to construct configurations that drive the HPCTONTIME, MPCTONTIME, and LPCTONTIME parameters in Diagnostics to a value less than a constant 100%.
The virtual controller is represented in the DeltaV system by the Assigned Modules subsystem on the ProfessionalPLUS or Application Station. There is one virtual controller per Assigned Modules subsystem. The number of virtual controllers in a DeltaV system is limited by the number of ProfessionalPLUS and Application Stations available in the system.
To configure the virtual controller, open DeltaV Explorer and expand the ProfessionalPLUS or Application Station node. Select and right-click Assigned Modules, and then select Assign from the context menu. Select Area (all modules in the area are assigned to the workstation), Process Cell (all modules in the process cell are assigned to the workstation), or Modules (individual modules are assigned to the workstation). Finally, download the workstation. The virtual controller supports running significantly more control modules than the physical controller due to the greater processing and memory capability of the workstation.
The following table lists the function blocks that are allowed in a control module assigned to a virtual controller.
If the control module contains a function block that is not listed here, the module cannot be successfully downloaded to a workstation.
|
Function block name |
Description |
Comments |
|---|---|---|
|
Advanced Control palette |
||
|
DIAG |
Diagnostic |
Not supported by OPC UA workstation clients. |
|
INSPECT |
Inspect Data Block |
Not supported by OPC UA workstation clients. |
|
LE |
Lab Entry |
Not supported by OPC UA workstation clients. |
|
MPC Analyzer Template |
MPC Analyzer Template |
Not supported by OPC UA workstation clients. |
|
MPC_INREF |
MPC Input Reference |
Not supported by OPC UA workstation clients. |
|
MPC_OUTREF |
MPC Output Reference |
Not supported by OPC UA workstation clients. |
|
MPC-PRO |
MPCPro |
Not supported by OPC UA workstation clients. |
|
MPC_SIM |
MPC Process Simulator |
Not supported by OPC UA workstation clients. |
|
Advanced Functions palette |
||
|
AVTR |
Analog Voter |
Not supported by OPC UA workstation clients. |
|
CEM |
Cause and Effect Matrix |
Not supported by OPC UA workstation clients. |
|
DVTR |
Discrete Voter |
Not supported by OPC UA workstation clients. |
|
STD |
State Transition Diagram |
|
|
SEQ |
Step Sequencer |
|
|
Analog Control palette |
||
|
AT |
Analog Tracking |
|
|
BG |
Bias/Gain |
|
|
CALC |
Calc/Logic |
|
|
DT |
Deadtime |
Not supported by OPC UA workstation clients. |
|
ERAMP |
Enhanced Ramp |
|
|
FLTR |
Filter |
|
|
ISEL |
Input Selector |
|
|
MANLD |
Manual Loader |
|
|
LL |
Lead/Lag |
Not supported by OPC UA workstation clients. |
|
LIM |
Limit |
|
|
PID |
||
|
RAMP |
Ramp |
|
|
RTLM |
Rate Limit |
|
|
SCLR |
Scaler |
|
|
SGCR |
Signal Characterizer |
|
|
SGGN |
Signal Generator |
|
|
SGSL |
Signal Selector |
|
|
SPLTR |
Splitter |
|
|
Energy metering |
||
|
AGA_SI |
Flow Metering in SI engineering units |
Not supported by OPC UA workstation clients. |
|
AGA_US |
Flow Metering in US engineering units |
Not supported by OPC UA workstation clients. |
|
ISE |
Isentropic Expansion |
Not supported by OPC UA workstation clients. |
|
SST |
Saturated Steam Properties - Given Temperature |
Not supported by OPC UA workstation clients. |
|
TSS |
Saturated Temperature |
Not supported by OPC UA workstation clients. |
|
SDR |
Steam Density Ratio |
Not supported by OPC UA workstation clients. |
|
STM |
Steam Properties |
Not supported by OPC UA workstation clients. |
|
WTH |
Water Enthalpy |
Not supported by OPC UA workstation clients. |
|
WTS |
Water Entropy |
Not supported by OPC UA workstation clients. |
|
IO palette |
||
|
ALM |
Alarm Detection |
|
|
AI |
Analog Input |
|
|
AO |
Analog Output |
|
|
DI |
Discrete Input |
|
|
DO |
Discrete Output |
|
|
PIN |
Pulse Input |
Not supported by OPC UA workstation clients. |
|
Logical palette |
||
|
ACT |
Action |
|
|
AND |
And |
|
|
BDE |
Bi-Directional Edge Trigger |
|
|
BFI |
Boolean Fan In |
|
|
BFO |
Boolean Fan Out |
|
|
CND |
Condition |
|
|
DC |
Device Control |
|
|
DCC |
Device Control Condition |
|
|
EDC |
EDC |
|
|
MLTX |
Multiplexer |
|
|
NDE |
Negative Edge Trigger |
|
|
NOT |
Not |
|
|
OR |
Or |
|
|
PDE |
Positive Edge Trigger |
|
|
RS |
RS Flip-Flop |
|
|
SR |
SR Flip-Flop |
|
|
XFR |
Transfer |
|
|
Math palette |
||
|
ABS |
Absolute Value |
|
|
ADD |
Add |
|
|
ARTHM |
Arithmetic |
|
|
CMP |
Comparator |
|
|
DIV |
Divide |
|
|
INT |
Integrator |
|
|
MLTY |
Multiply |
|
|
SUB |
Subtract |
|
|
Timer Counter palette |
||
|
CTR |
Counter |
|
|
DTE |
Date Time Event |
|
|
OFFD |
Off-Delay Timer |
|
|
OND |
On-Delay Timer |
|
|
RET |
Retentive Timer |
|
|
TP |
Timed Pulse |
|