Pointer Objects

Description
Operation
Properties

Examples
Related
Version History & Bug list

A Pointer Object is used to specify where to find information in another Object. It does not store the information itself, instead each time the information is needed, the Pointer is used to identify where to retrieve the information from or store the information to.

A Pointer can be changed at any time during the execution of the applications program allowing the source or destination of the data flow to change dynamically.

All of the predefined ooPIC objects use two types of pointers.

A pointer to an oValue Object. Typically the target Object's Default property is an oValue property or has an oValue property in its default path. These type of pointers are referred to as an oValue Pointer (example: oBus has two oValue pointers. One for its input and one for its output.)
A pointer to an oLogic Object. Often, the target Object will have a number of oLogic properties. These type of pointers are referred to as an oLogic Pointer. (example: oGate has oLogic Pointers).

The following table lists the size and availability of the Pointer Objects.

Object	Size	Description	A1	A2	B1	B2	C1
oValuePtrI	1 Byte	A pointer to an oValue Object who's value will be used as an input.	x	x	x	x	x
oValuePtrO	1 Byte	A pointer to an oValue Object who's value will be used as an output.	x	x	x	x	x
oLogicPtrI	1 Byte	A pointer to an oLogic Object who's value will be used as an input.	x	x	x	x	x
oLogicPtrO	1 Byte	A pointer to an oLogic Object who's value will be used as an output.	x	x	x	x	x

Operation:

The Pointer property holds the actual address of the object that is being pointed to. During the operation of a Virtual Circuit, this property is used to identify where to retrieve the information from or store the information to.

A Link Method is provided to automate the assignment of the Pointer property to the address of an object.

Properties:

The following table lists the properties of the Pointer Object:

Property
Description

Pointer

The memory address of an oValue Object.

Object Class: oVar7 Value Range: 0 - 127

Data Type: Pointer Default Value: 0

Address

Returns a pointer to the address of the Pointer Object instance.

Object Class: oAddress Value Range: 0 - 127

Data Type: Pointer (Read Only) Default Value: Address of Object

Methods

The following table lists the properties of the Pointer Object:

Methods
Description

Link

Sets the Pointer property to the address of the given Object.

Clear

Clears the Pointer property to null. (0)

Example:

For examples, see the oWire and oBus objects.