Control Link

Navigation: Main Page -> Models -> Control 2 Models

---

General Description

When the following units are linked together using the insert link function, a control link is made.

• Transmitter & PID control measured value
• PID control output value & Valve opening (dynamic only)
• PID control output value & Pump speed (dynamic only)
• PID control output value & Actuator (mainly for dynamic)

Diagram

Model Theory

The transmitter model can be connected to a PID unit by a control link. To connect, use the insert link function, and select the transmitter as the source and the PID meas(ured value) as the destination. When the connection is made, the transmitter tag will be automatically put into the PID control block.

The PID unit can be connected to a valve/pump/actuator by a control link. To connect, use the insert link function, and select the PID output value as the source and the valve/pump/actuator as the destination. When the connection is made, the PID output tag will be set to the valve opening/pump speed/actuator tag.

Note: valve opening and pump speed will use fractions only.

Data Sections

Summary of Data Sections

1. CtrlLink tab - Contains general information relating to the unit.
2. Info tab - Contains general settings for the unit and allows the user to include documentation about the unit and create Hyperlinks to external documents.

Control Link Page

Unit Type: CtrlLink - The first tab page in the access window will have this name.

Tag (Long/Short)	Input / Calc	Description/Calculated Variables / Options
Tag	Display	This name tag may be modified with the change tag option.
Condition	Display	OK if no errors/warnings, otherwise lists errors/warnings.
ConditionCount	Display	The current number of errors/warnings. If condition is OK, returns 0.
GeneralDescription / GenDesc	Display	This is an automatically generated description for the unit. If the user has entered text in the 'EqpDesc' field on the Info tab (see below), this will be displayed here. If this field is blank, then: For pipes, SysCAD will use the text in the 'ConnectDesc' field - this displays the Source and Destination tags of the pipe; For Feeders/Cross Page Connectors, SysCAD will display the state of the unit, i.e. if it is a Feeder or a Sink, etc.; For other units SysCAD will display the unit class ID.
On	Tick Box	The control link will be enabled or disabled using this box.
Value	Output	The input variable's value.
SrcIO	Output	The tag of the source unit.
DstIO	Output	The tag of the destination unit.

Adding this Model to a Project

Insert into Configuration file

Sort either by DLL or Group.

	DLL:	Control1.dll	→	Units/Links	→	IO - CtrlLink
or	Group:	General	→	Units/Links	→	IO - CtrlLink

See Project Configuration for more information on adding models to the configuration file.

Insert into Project

See Insert Link for general information on inserting links.