Skip to content

ADS.md

Latest commit

 

History

History
49 lines (38 loc) · 1.84 KB

ADS.md

File metadata and controls

49 lines (38 loc) · 1.84 KB

AdsReadWrite

Cyclic component that wraps TwinCAT ADS read/write function blocks. Provides both index-group/offset-based access and symbol-name-based access to variables on any ADS-reachable runtime.

Extends: CyclicComponent
Implements: I_AdsRW

Interface

Member Type Description
FB_Init(Name) Constructor Standard component name
AmsNetId T_AmsNetId (Get/Set) Target runtime AMS Net ID
AmsPort T_AmsPort (Get/Set) Target AMS port
AdsComMode E_AdsComMode (Set) Communication mode; default eAdsComModeSecureCom
Busy BOOL (Get) TRUE while any read or write is in progress
Error BOOL (Get) TRUE if any operation has faulted
ErrorId UDINT (Get) ADS error code of the most recent fault
Read(IdxGrp, IdxOffset, pDestAddr, Length) Method Triggers an index-group read
ReadBySymbol(SymbolName, pDestAddr, Length) Method Reads a variable by its symbol name
Write(IdxGrp, IdxOffset, pSourceAddr, Length) Method Triggers an index-group write
WriteBySymbol(SymbolName, pSourceAddr, Length) Method Writes a variable by its symbol name
CyclicLogic() Method Must be called each scan; services all pending operations

Notes

  • Only one read and one write can be in-flight at a time; calls while Busy are silently dropped.
  • CyclicLogic() resets the execute flags each scan — no manual reset required.

Example

VAR
    Ads      : AdsReadWrite('RemoteAds');
    MyValue  : DINT;
END_VAR

Ads.AmsNetId := '192.168.1.10.1.1';
Ads.AmsPort  := 851;

// Read a variable by symbol name
Ads.ReadBySymbol('MAIN.Counter', ADR(MyValue), SIZEOF(MyValue));
Ads.CyclicLogic();

// Write by symbol name
MyValue := 42;
Ads.WriteBySymbol('MAIN.Counter', ADR(MyValue), SIZEOF(MyValue));
Ads.CyclicLogic();