Hello to all TwinCAT developers,
I am currently developing function blocks with TwinCAT.
I'm trying to find a "standard" way to interact with the outside of the block.
The Beckhoff examples always have a bExec signal to start a state machine on the rising edge.
fbRisingEdge(CLK := bExec);
IF fbRisingEdge.Q THEN
nStep := 1;
END_IF
CASE nStep OF
1:
nStep := nStep + 1;
2:
nStep := nStep + 1;
END_CASE
I find that this principle is heavy to use and requires more code to create the rising edge:
fbFileOpen(sPathName := sPathName, bExecute := FALSE);
fbFileOpen(sPathName := sPathName, bExecute := TRUE);
Would anyone use another alternative to start a state-machine inside a FB?
Thank you, Happy new year!
I use a method defined inside my function block to trigger an action. I Also (sometimes) return a bool from the method which indicates weather the action can be performend or not, depending on the current state.
METHOD M_Open : BOOL
VAR_IN
sPath : STRING;
END_VAR
VAR_OUTPUT
bExecutionAllowed : BOOL;
END_VAR
bExecutionAllowed := _ ; // Calculate depending on the current state
sPathName := sPath;
IF bExecutionAllowed THEN
nStep := 1;
END_IF
Then call the method somewhere once
fbFileHandler.M_Open("Path/To/File");
And the fucntion block cyclically
fbFileHandler();
The function block can than handles multiple different actions which may be triggered each by their own method.
Related
I am writing which component will run through the array like ['form1.Button1', 'form1.memo1', 'form1'] - like
And put the showms2 handler on it (form1.Button1.onclick: = showms2)
var
comp: array of Tcomponent;
met: Tmethod;
start off
setlength (comp, Lines.Count);
for i: = 0 to Lines.Count-1 do
start off
comp [i]: = (FindComponent (Lines.Names [i]) as TControl);
met: = GetMethodProp (comp [i], 'OnClick');
meth.Code: = form1.MethodAddress ('showms2');
met.Data: = 0;
// When splitting into elements, nothing happens, is there an alternative?
FindComponent() does not work the way you are using it. You need to specify only the name of a component that is directly owned by the component being searched, you can't specify a chain of components, ie Form1.FindComponent('Form1.Button1') won't ever work, but Form1.FindComponent('Button1') will work, if Form1 owns Button1.
Also, if you are going to set both TMethod.Code and TMethod.Data then calling GetMethodProp() is completely redundant and should be removed.
Also, you need to use SetMethodProp() to actually assign the TMethod to the target event.
Try this instead:
var
comp: TComponent;
met: TMethod;
i: Integer;
begin
for i := 0 to Lines.Count-1 do
begin
comp := FindComponent(Lines.Names[i]);
if comp <> nil then
begin
if IsPublishedProp(comp, 'OnClick') then
begin
meth.Code := Form1.MethodAddress('showms2');
meth.Data := Form1;
SetMethodProp(comp, 'OnClick', met);
end;
end;
end;
end;
When calling a method of a function block, is it possible to make certain input variables optional? If I call fbA.methA() without assignments for all input variables, TwinCAT throws an error: "Function methA requires exactly 'x' inputs." There are times when some inputs are unnecessary or irrelevant, but so far I've had to assign dummy values to those inputs to get the code to compile.
I don't think that that is possible. You could make extra methods which all call a base method.
For example:
FUNCTION_BLOCK Multiplier
METHOD Multiply : REAL
VAR_INPUT
number1 : REAL;
number2 : REAL;
END_VAR
METHOD MultiplyByTwo : REAL
VAR_INPUT
number : REAL;
END_VAR
MultiplyByTwo := Multiply(2, number);
That way you also reduce the number of inputs of your method, thereby making it easier to test and use.
You also could screen the parameters as they are passed in (still requires parameters but they have no meaning aka always pass "0").
FUNCTION_BLOCK CAT
METHOD DECIBELS: REAL
VAR_INPUT
MEOW, PURR: BOOL;
END_VAR
// body
DECIBELS := 0.0;
IF MEOW <> 0
DECIBELS := DECIBELS + 10.0;
END_IF;
IF PURR <> 0
DECIBELS := DECIBELS + 5.0;
END_IF;
END_METHOD
END_FUNCTION_BLOCK
you can invoke this like:
PROGRAM MAIN
VAR
C: CAT;
RESULT: ARRAY [1..4] OF REAL;
END_VAR
// body
RESULT[1] := C.DECIBELS(TRUE, TRUE); // will return 15.0
RESULT[2] := C.DECIBELS(TRUE, 0); // will return 10.0
RESULT[3] := C.DECIBELS(0, TRUE); // will return 5.0
RESULT[4] := C.DECIBELS(0, 0); // will return 0.0
END_PROGRAM
Hope this helps
The Windows ribbon framework markup supports an EnablePinning attribute for the recent items menu in the application menu:
<ApplicationMenu.RecentItems>
<RecentItems CommandName="MRU" EnablePinning="true" />
</ApplicationMenu.RecentItems>
I expected that there would be a matching property that can be queried/updated at runtime, but I can't find a property key. Does anyone know if there is one, and, if so, what it is?
Alternatively, is there another way to turn pinning on/off at runtime? Neither the element nor its parent support application modes.
TIA
Clarification: What I'm trying to do is enable/disable pinning for the entire menu at runtime. I'm not concerned about the pin states of the individual items.
I'm not sure if you can modify the pinned state from existing entries but it's definitely possible to programmatically query the state and add new items with a specific state using the UI_PKEY_Pinned property:
https://msdn.microsoft.com/en-us/library/windows/desktop/dd940401(v=vs.85).aspx
Wrappers such as the Windows Ribbon Framework for Delphi or the Windows Ribbon for WinForms (.NET) provide an easy access to the API model. This CodeProject article also describes how to query/add recent items using C#.
If you want to change the state during runtime, you could for example query the state of all items, remove them from the list, adjust whetever you need and add them to the list again. Didn't do that yet, could be worth a try however.
Hmm... this will be quite difficult to accomplish as the flag is defined in the XML which will be compiled into a resource file that is linked to the application and then loaded on start up. You could create another resource definition and reload the ribbon if you want to disable/enable the flagging, but that's quite a lot overhead and certainly noticeable from an users perspective as it requires the creation of a new window handle.
I place the recent items by inside UpdateProperty
TRecentItem = class(TInterfacedObject, IUISimplePropertySet)
private
FRecentFile: TSSettings.TRecentFile;
protected
function GetValue(const key: TUIPropertyKey; out value: TPropVariant): HRESULT; stdcall;
public
procedure Initialize(const RecentFile: TSSettings.TRecentFile); safecall;
end;
function TMyForm.UpdateProperty(commandId: UInt32; const key: TUIPropertyKey;
currentValue: PPropVariant; out newValue: TPropVariant): HRESULT;
var
I: Integer;
psa: PSafeArray;
pv: Pointer;
RecentItem: TRecentItem;
begin
if (key = UI_PKEY_RecentItems) then
begin
psa := SafeArrayCreateVector(VT_UNKNOWN, 0, Settings.RecentFiles.Count);
if (not Assigned(psa)) then
Result := E_FAIL
else
begin
for I := 0 to Settings.RecentFiles.Count - 1 do
begin
RecentItem := TRecentItem.NewInstance() as TRecentItem;
RecentItem.Initialize(Settings.RecentFiles[I]);
pv := Pointer(IUnknown(RecentItem));
Check(SafeArrayPutElement(psa, I, pv^));
end;
Result := UIInitPropertyFromIUnknownArray(UI_PKEY_RecentItems, psa, PropVar);
SafeArrayDestroy(psa);
end;
end;
If a pin was changed, I get this command while closing the application menu:
function TMyForm.Execute(commandId: UInt32; verb: _UIExecutionVerb;
key: PUIPropertyKey; currentValue: PPropVariant;
commandExecutionProperties: IUISimplePropertySet): HRESULT; stdcall;
var
Count: Integer;
I: Integer;
Pinned: Boolean;
psa: PSafeArray;
pv: IUnknown;
RecentFile: UInt32;
SimplePropertySet: IUISimplePropertySet;
Value: TPropVariant;
begin
if ((commandId = cmdAppRecentItems)
and Assigned(key) and (key^ = UI_PKEY_RecentItems)
and Assigned(currentValue) and (currentValue^.vt = VT_ARRAY + VT_UNKNOWN)) then
begin
psa := nil;
Result := UIPropertyToIUnknownArrayAlloc(key^, currentValue^, psa);
if (Succeeded(Result)) then
begin
Result := SafeArrayGetUBound(psa, 1, Count);
for I := 0 to Count do
if (Succeeded(Result)) then
begin
Result := SafeArrayGetElement(psa, I, pv);
if (Succeeded(Result) and Assigned(pv)) then
begin
Result := pv.QueryInterface(IUISimplePropertySet, SimplePropertySet);
if (Succeeded(Result)) then
Result := SimplePropertySet.GetValue(UI_PKEY_Pinned, Value);
if (Succeeded(Result)) then
Result := UIPropertyToBoolean(UI_PKEY_Pinned, Value, Pinned);
if (Succeeded(Result)) then
Settings.RecentFiles.SetPinned(I, Pinned);
end;
end;
SafeArrayDestroy(psa);
end;
end
end;
... but I didn't find a documentation of this solution.
here is my code:
function GetProcedureAddress(var P: FARPROC; const ModuleName, ProcName: AnsiString): Boolean;
var
ModuleHandle: HMODULE;
begin
Result := False;
ModuleHandle := GetModuleHandle(PAnsiChar(AnsiString(ModuleName)));
if ModuleHandle = 0 then
ModuleHandle := LoadLibrary(PAnsiChar(ModuleName)); // DO WE NEED TO CALL FreeLibrary ?
if ModuleHandle <> 0 then
begin
P := Pointer(GetProcAddress(ModuleHandle, PAnsiChar(ProcName)));
if Assigned(P) then
Result := True;
end;
end;
function PathMakeSystemFolder(Path: AnsiString): Boolean;
var
_PathMakeSystemFolderA: function(pszPath: PAnsiChar): BOOL; stdcall;
begin
Result := False;
if GetProcedureAddress(#_PathMakeSystemFolderA, 'shlwapi.dll', 'PathMakeSystemFolderA') then
Result := _PathMakeSystemFolderA(PChar(Path));
end;
DO we need to call FreeLibrary if using LoadLibrary? or it's reference count will decremented automatically when my application terminates?
I will quote from here.
The system maintains a per-process reference count on all loaded modules. Calling LoadLibrary increments the reference count. Calling the FreeLibrary or FreeLibraryAndExitThread function decrements the reference count. The system unloads a module when its reference count reaches zero or when the process terminates (regardless of the reference count).
So basically you don't need to call FreeLibrary but you should think about doing so. I personally think it is a bug when resources are not handled correctly.
I want to develop a setup package for conditionally upgrading an existing package. I want to check the existing software version against to-be-installed version. In order to do that, I have to compare the version strings.
How can I convert the string value to a numerical value in a Inno setup script?
RegQueryStringValue(HKEY_LOCAL_MACHINE, 'Software\Blah blah', 'Version', version)
version = 'V1.R2.12';
numVersion := ??string_to_numerical_value??(version);
This is a little more tricky, as you would want to handle versions like 'V1.R2.12' and 'V0.R15.42' correctly - with the simple conversion in the other answer you would get 1212 and 1542, which would not compare the way you would expect.
You need to decide how big each part of the version number can be, and multiply the parts by that value to get a correct end number. Something like this:
[Code]
function string_to_numerical_value(AString: string; AMaxVersion: LongWord): LongWord;
var
InsidePart: boolean;
NewPart: LongWord;
CharIndex: integer;
c: char;
begin
Result := 0;
InsidePart := FALSE;
// this assumes decimal version numbers !!!
for CharIndex := 1 to Length(AString) do begin
c := AString[CharIndex];
if (c >= '0') and (c <= '9') then begin
// new digit found
if not InsidePart then begin
Result := Result * AMaxVersion + NewPart;
NewPart := 0;
InsidePart := TRUE;
end;
NewPart := NewPart * 10 + Ord(c) - Ord('0');
end else
InsidePart := FALSE;
end;
// if last char was a digit the last part hasn't been added yet
if InsidePart then
Result := Result * AMaxVersion + NewPart;
end;
You can test this with the following code:
function InitializeSetup(): Boolean;
begin
if string_to_numerical_value('V1.R2.12', 1) < string_to_numerical_value('V0.R15.42', 1) then
MsgBox('Version ''V1.R2.12'' is not as recent as version ''V0.R15.42'' (false)', mbConfirmation, MB_OK);
if string_to_numerical_value('V1.R2.12', 100) > string_to_numerical_value('V0.R15.42', 100) then
MsgBox('Version ''V1.R2.12'' is more recent than version ''V0.R15.42'' (true)', mbConfirmation, MB_OK);
Result := FALSE;
end;
Whether you pass 10, 100 or 1000 for AMaxVersion depends on the number and range of your version number parts. Note that you must not overflow the LongWord result variable, which has a maximum value of 2^32 - 1.
I haven't tried that (and my Pascal knowledge is a bit rusty), but something like the following should work:
function NumericVersion(s: String): Integer;
var
i: Integer;
s1: String;
begin
s1 := '';
for i := 0 to Length(s)-1 do
if (s[i] >= '0') and (s[i] <= '9') then
s1 := s1 + s[i];
Result := StrToIntDef(s1, 0);
end;
Please not that you'll have to play with the start and end value for i as I'm not sure whether it is zero-based or not (s[0] may contain the length of the string if it is a "Pascal String").
I've implemented two version strings (actually one string and one dword value) in the registry to overcome complexity.
displayversion="v1.r1.0"
version="10100" (=1*10^4 + 1*10^2 + 0*10^0)
That's simple. Though not an answer to this question, however one might think the other way around when faced with complexity, which could be avoided in a simpler way.