In OLGA 6 the controllers are signal components. Signal components are a special kind of network components, able to transfer signals between each other. Coupling in the signal network is possible between the following components (notice that a controller is always involved):
· Pipeline section variable (via a transmitter) to controller
This chapter describes how to connect signal components in the GUI.
Signal network terminology
The following explanations of the terminology used for signal networks can make it easier to understand how controllers are connected to other components.
A signal component is a component that can send and/or receive a signal. A signal component (e.g. a controller) is connected to other signal components (e.g. a flowpath) via terminals.
Terminals are best explained with an example; A PID Controller has 3 terminals, 2 for receiving signals (the setpoint signal terminal and the measured signal terminal) and one for sending signals (the output signal terminal). Another signal component like a separator can send its holdup value as a signal to the PID Controller. The holdup will be sent via the measured signal terminal of the controller. The PID Controller will calculate an output signal based on the measured value and send it via the output signal terminal to e.g. a valve.
A signal is just a value. There isn’t much difference between a signal in a signal network and a flow in a flow network. The flow represents a physical flow of oil, gas or water while the signal can represent anything. The meaning of the signal to the signal component depends on which terminal that is used to send the signal. In the example above the signal represented a measured value since it was sent via the measured signal terminal.
A flowpath may send measured values as signals. To do this one must add a transmitter to the flowpath.
The transmitter acts as an output signal terminal for the flowpath. Most inline process equipment added to the flowpath can act as a signal terminal for the flowpath in the same way as a transmitter (you may for example connect a controller directly to a valve).
Graphical configurations of controller connections
Coupling of signal components is possible with two different techniques in the graphical user interface;
i) Coupling with drag and drop or -ii)Coupling through the connection view Drag and drop coupling
The drag and drop coupling between two signal components is done in the same manner as between two multiphase network components:
3. Choose one of the available terminals to connect from (only OUTSIG_1 is available in the figure above) and a terminal to connect to (MEASRD and SETPOINT is available in the figure above). A connection between the two components is created.
4. Select variable to transmit.
If the coupling is between a transmitter and a controller, a variable to be transmitted has to be given.
Setting this variable must be done in the connection view
Coupling using the connection view
The drag and drop technique for coupling components in the signal network is less practical when the case is large with many components. Dragging from one component to another may involve zooming to view both components, and thereby making the coupling difficult.
It is possible to connect signal components using the connection view without seeing the other components.
In the figure below the connections for a PID-controller is shown. All terminals (in-/out-signals) for controller CNTRL-1 are listed in column one (Terminal). Column two (Connected NC) and three (Connected terminal) lists which network components and terminals the controller is connected to. If a user-chosen variable is supposed to be transmitted column four (Variable) is used.
The connection view has two modes. The above figure shows connections for a selected component.
The other mode is for showing all connections in the case. In this mode it is easier to see the direction of the signals (see figure below)
Hiding and deleting connections
If there are many controllers the case may be too complicated to get a good overview. In such cases you may hide the controllers and their connections. Do this by right clicking on a controller and select 'Hide'.
To hide all controllers select 'Hide all of this type'.
If you have connected a controller by mistake you may delete the connection by selecting it and pressing the 'Delete' button. NOTE: If you delete a controller the connection is not deleted automatically - you have to select the connection and press the 'Delete' button.
is coupled to flowpaths and nodes.
Graphical configuration and multiphase coupling of separator
The multiphase coupling of a separator is made in the same manner as a multiphase coupling between a node and a flow path.
Add a node and a separator to your case from the component view.
Connect a flowpath from the node to the separator as follows:
1. Click the node and drag.
2. Release on separator.
3. A context menu will display which out-terminals on the node it is possible to connect from and which in-terminals on the separator it is possible to connect to. In the figure below the flow path is connected to the inlet terminal of the separator
Add another node to your case.
Connect a flowpath from one of the separator outlets to the node as follows:
1. Click the separator and drag.
2. Release on the node.
3. A context menu will display which out-terminals on separator it is possible to connect from and which in-terminals on the node it is possible to connect to. In the figure below the flow path is connected from the gas outlet terminal of the separator to node 1. The oil outlet terminal of the separator is connected via another flowpath to node 2.
See also:
When to use
Methods and assumptions Limitations
How to use