[NumLock]

Код:

unit Unit2;

interface

uses
  SysUtils, Classes, DB, DBTables;

type
  TDataModule2 = class(TDataModule)
    Database1: TDatabase;
  private
    { Private declarations }
  public
    { Public declarations }
    procedure Connect;
  end;

var
  DataModule2: TDataModule2;

implementation

{$R *.dfm}

{ TDataModule2 }

procedure TDataModule2.Connect;
begin
  Database1.Connected:=True;
end;

end.

Код:

unit Unit1;

interface

uses
  Unit2,
...
begin
  DataModule2.Connect;
end;