Actuator

NOTE: This feature is distributed with SysCAD but is currently in BETA. Please contact us ([email protected]) if you run into any issues using this model. This page is currently under development and details may change. Use with caution - we do not guarantee compatibility between different BETA versions.

Navigation: Models ➔ Control 2 Models ➔ Actuator

---

General Description

The Actuator is used to get a value from a PID block and then change the value of a tag in the model. Its use is not required since a PID block can directly access tags. However, it can add value by better displaying the control logic on a flowsheet and representing the equipment in the field.

Model Theory

The actuator can be a standalone unit - it does not need to be connected to any other unit operation.

Note: The actuator output_tag must be a writeable field, e.g. Feeder.Qm_Rqd.

Data Sections

Summary of Data Sections

1. Actuator 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.

Actuator Page

Unit Type: Actuator - 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 SysCAD will display the UnitType or SubClass.
On	Tick Box	All of the independent Actuators will be enabled or disabled using this box.
Count	Input	The number of independent Actuators required. The default is 1. The user may also change this number at any time. However, the unit will always add new Actuator after existing ones, and it will delete them starting from the last Actuator. E.g. if you have 5 Actuators set up and you change this to 4, Actuator number 5 will be deleted.
ShowCnv	Tick Box	With this option selected, SysCAD will display engineering units for tags. Note that these will only be displayed after SysCAD has completed at least one iteration.
Check Tags	Button	SysCAD will perform a check on the validity of the tag(s).
State	Output	The state of the Actuator. If everything is correct and operating normally, the user will see OK in this box. Otherwise the unit will flag an error message, which helps the user to locate the problem with the controller.
Errors:
MSG_1 to MSG_2	Output	Any errors will be reported here. These messages are also displayed in the message window.
Each independent Actuator has the following layout. The first Actuator will be displayed on the first page. Each page thereafter displays multiple actuators.
Tag.Cfg.[Actuator number]
ID	Input	This will be the same name as the Output tag if not specified.
OutputTag	Input	The output variable, it must be a valid tag name and it must be write-able. The user may type the tag in, however it is preferable to use the cut and paste function to avoid any typing errors.
RequiredValue	Output	The output variable's value.

Note: The remaining variables are used in Dynamic simulations in conjunctions with control system testing. They have no significance in ProBal thus not documented.

Adding this Model to a Project

Insert into Configuration file

Sort either by DLL or Group.

	DLL:	Control1.dll	→	Units/Links	→	Control 2: Actuator
or	Group:	General	→	Units/Links	→	Control 2: Actuator

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

Insert into Project

Insert Unit

→

Control 2

→

Actuator

See Insert Unit for general information on inserting units.