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Questo esempio serve per creare una dll che poi verrà caricata su un software di automatismi vorrei capirci qualcosa e poi modificare tale sorgente.
Example DLL source (Delphi)
The compiled DLL file can be found in the EXAMPLES directory (COUNTER.DLL).
codice:library Counter; // Delphi 5 DLL-source (COUNTER.DLL) // Defines a simple 8-Bit counter component for ProfiLab uses SysUtils,Windows,Classes; {$R *.RES} Const Inputs = 2; // number of inputs Outputs = 8; // number of outputs {INPUTS} CLK = 0; // index of input variable CLK RST = 1; // index of input variable RST {OUTPUTS} {USER} CLK_old = 0; // index user variable CLK_old RST_old = 1; // index user variable RST_old Count = 2; // index user variable COUNT Type TDLLParams = array[0..100] of extended; //Type of ProfiLab DLL parameters PDLLParams = ^TDLLParams; // Pointer to ProfiLab DLL parameters function NumInputs: Byte; begin result:=Inputs; //Define number of component input pins end; function NumOutputs: Byte; begin result:=Outputs; //Define number of component output pins end; Function InputName(Channel: Byte): ShortString; // Return name for each component input pin begin case Channel of CLK: result:='CLK'; // "CLK" (Clock) RST: result:='/RST'; // "/RST" (NOT RESET) end; end; Function OutputName(Channel: Byte): ShortString; // Return name for each component output pin begin result:='Q'+intToStr(Channel); //"Q0".."Q7" (Binary count) end; Procedure SimStart(PInput,POutput,PUser: PDLLParams); //called when ProfiLab enters RUN mode var i: Integer; begin PUser^[Count]:=0; //RESET COUNTER For i:=0 to Outputs do begin POutput[i]:=0; //Set binary outputs with COUNT=0 end; end; Procedure SimStop(PInput,POutput,PUser: PDLLParams); //called when ProfiLab RUN mode is terminated begin // nothing to be done end; Procedure Calculate(PInput,POutput,PUser: PDLLParams); //called regularly from ProfiLab var i: Integer; begin if PInput^[RST]<2.5 then //check RST input HIGH or LOW begin if (not (PInput^[RST]>=2.5)) and (PUser^[RST_old]>2.5) then //check out falling edge at RST input begin PUser^[Count]:=0; //RESET COUNT For i:=0 to Outputs do begin POutput[i]:=0; //Set binary outputs with COUNT=0 end; end; exit; end; PUser^[RST_old]:=PInput^[RST]; //Remember RST status for next call if PInput^[CLK]>2.5 then //check CLK input HIGH or LOW begin if (PInput^[CLK]>2.5) and not(PUser^[CLK_old]>2.5) then //check out rising edge at CLK input begin PUser^[Count]:=PUser^[Count]+1; // increase COUNT if PUser^[Count]>255 then PUser^[Count]:=0; //check overflow For i:=0 to Outputs do begin if (round(PUser^[Count]) and (1 shl i))>0 then POutput^[i]:=5 else POutput[i]:=0; //Set binary outputs with current COUNT end; end; end; PUser^[CLK_old]:=PInput^[CLK]; //Remember CLK status for next call end; //export methods for ProfiLab exports SimStart, SimStop, NumInputs, NumOutputs, Calculate, InputName, OutputName; begin end.
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