IAdsSymbolicAccess Interface

Interface for symbolic ADS access (Read or Write)

Namespace: TwinCAT.Ads
Assembly: TwinCAT.Ads.Abstractions (in TwinCAT.Ads.Abstractions.dll) Version: 7.0.0+e56d35ccc4675faac24789a4aab60071fc61d470

Syntax

C#

public interface IAdsSymbolicAccess

The IAdsSymbolicAccess type exposes the following members.

Methods

	Name	Description
	CleanupSymbolTable	Clears the internal symbol / DataTypes cache.
	ReadDataType	Reads/Determines the DataType Inforrmation with the specifed name.
	ReadDataTypeAsync	Reads/Determines the DataType of the specified type as an asynchronous operation.
	ReadSymbol	Reads the symbol information about an individual variable in ADS devices.
	ReadSymbolAsync	Reads the symbol information object specified by the instance path as an asynchronous operation.
	ReadValue(ISymbol)	Reads the value of a symbol and returns the value as (boxed) object.
	ReadValue(String)	Reads the value of a symbol specified with its instance path and returns the value as boxed object.
	ReadValue(String, Type)	Reads the value of a symbol specified with its instance path and returns the value as object of the specified type.
	ReadValueT(ISymbol)	Reads the value of a symbol and returns it as an typed object.
	ReadValueT(String)	Reads the value of a symbol and returns the value as specified type.
	ReadValueAsync(ISymbol, CancellationToken)	Reads the value of a symbol as an asynchronous operation and returns the value as an (boxed) object.
	ReadValueAsync(String, Type, CancellationToken)	Reads the typed value of a symbol as an asynchronous operation.
	ReadValueAsyncT(ISymbol, CancellationToken)	Reads the value of a symbol as an asynchornous operation and returns the value of the specified type.
	ReadValueAsyncT(String, CancellationToken)	Reads the typed value of a symbol specified by the instance path as an asynchronous operation.
	TryReadDataType	Tries to Read/Determine the DataType of the specified type.
	TryReadSymbol	Tries to read the symbol information object specified by the instance path.
	TryReadValue(ISymbol, Object)	Tries to read the value of a symbol and returns the value as boxed object.
	TryReadValue(String, Type, Object)	Tries to the value of a symbol specified as instance path and returns the value as (boxed) object.
	TryReadValueT(ISymbol, T)	Reads the value of a symbol and returns the value as typed value.
	TryReadValueT(String, T)	Tries to reads the value of a symbol specified with instance path and returns the typed value.
	TryWriteValue(ISymbol, Object)	Tries to write a (boxed) value to the symbol
	TryWriteValue(String, Object)	Tries to write a (boxed) value to the symbol instance specified by its instance/symbol path.
	TryWriteValueT(ISymbol, T)	Tries to write a value to the symbol.
	TryWriteValueT(String, T)	Tries to Write a (typed) value to the symbol instance specified by its instance/symbol path.
	WriteValue(ISymbol, Object)	Writes a (boxed) value to the symbol.
	WriteValue(String, Object)	Writes a (boxed value) to the symbol instance specified by its instance/symbol path.
	WriteValueT(ISymbol, T)	Writes a (typed) value to the symbol.
	WriteValueT(String, T)	Writes a typed value to the symbol instance specified by its instance/symbol path.
	WriteValueAsync(ISymbol, Object, CancellationToken)	Writes a (boxed) value to the symbol as an asynchronous operation.
	WriteValueAsyncT(ISymbol, T, CancellationToken)	Writes a (typed) value to the symbol as an asynchronous operation.
	WriteValueAsyncT(String, T, CancellationToken)	Writes a (typed) value to the symbol instance specified by its instance/symbol path as an asynchronous operation.

Remarks

To convert the read ADS value to its appropriate .NET type or writing to ADS, the following rules take place:

For primitive types including strings or arrays of primitives, no type parameter is necessary. A default marshalling to the most appropriate type will be done.
If a primitive type (including primitive array or string) is given as type, the result value will be converted if possible to that type. If the value is not convertible, this method fails.
If the type is complex (e.g. structs), the ADS value must be blittable to the specified type (same size, same binary layout), must be convertible by reflection (each field can be recognized via its name and their types are compatible/convertable) or a custom marshalling must be available.

For writing values:

The used type is given by the .NET value type
for Primitive types including strings or arrays of primitives, a default marshalling takes place.
If a type parameter is part of the Write interface method, the given value will be converted to that type if possible. If the value is not convertible, this method fails.
If the type is complex (e.g. structs), the ADS value must be blittable to the specified type (same size, same binary layout), must be convertible by reflection (each field can be recognized via its name and their types are compatible/convertable) or a custom marshalling must be implemented.
If a string is passed as parameter, the method attempts to parse the string according to the ADS data type of the symbol.

Reference

TwinCAT.Ads Namespace

Beckhoff Automation GmbH & Co. KG 2001-2026

Further Information

IAdsSymbolicAccess Methods