Force feeder acquiring with v15 API with Delphi

Hello.
I using Lead Tools v15 API with Delphi.
I want to drive a scanner to capture many documents setting three parameters from my application:
1 - Resolution 300x300
2 - Bit per pixel 1
3 - Force acquiring from feeder
I tried to do that with this code:

X.Whole := 300;
Y.Whole := 300;
L_TwainSetResolution(hSession, @X, @Y);
L_TwainSetImageBitsPerPixel(hSession, 1);

This code works correctly, but there is not a function that allows me to force the acquisition from feeder (I did not found it).
First question: there is a *L_TwainSetPaperSource* function to add at the previous code?

Then I tried to use the following code, which should make it possible to set all the three parameters:

ZeroMemory(@Params, sizeof(LTWAINPROPERTIES));
L_TwainStartCapsNeg(hSession);
L_TwainGetProperties(hSession, @Params, sizeof(LTWAINPROPERTIES), LTWAIN_PROPERTIES_GETCURRENT);
L_TwainEndCapsNeg(hSession);
Params.ImageRes.nBitsPerPixel := 1;
Params.ImageRes.fHorzResolution := 300;
Params.ImageRes.fVertResolution := 300;
Params.bPaperSource := True;
L_TwainStartCapsNeg(hSession);
L_TwainSetProperties(hSession, @Params, LTWAIN_PROPERTIES_SET, nil, nil);
L_TwainEndCapsNeg(hSession);

The result of using this code is that I can set only the resolution, while the other parameters remain not set.
Second question: what is my mistake?
Third question: there another way to set these three parameters at run time?

Regards

Franco

Please try
to use the L_TwainSetCapability and set the "CAP_FEEDERENABLED" capability to TRUE, does this fix your issue?

I have tested what you suggested, also copying something from the examples that there are in documentation.
It seems to work fine.
I have set resolution and bits per pixel with the specific functions and the feeder with
L_TwainSetCapability.
Here is the code I made (for who develops with Delphi):

var
nRet: L_INT;
X, Y: TW_FIX32;
twCap: TW_CAPABILITY;
pOneVal: pTW_ONEVALUE;
begin
L_TwainStartCapsNeg(hTwnSession);
// set resolution
X.Whole := 300;
Y.Whole := 300;
L_TwainSetResolution(hTwnSession, @X, @Y);
// set bits per pixel
L_TwainSetImageBitsPerPixel(hTwnSession, 1);
// force feeder
twCap.Cap:= CAP_FEEDERENABLED;
twCap.ConType:= TWON_ONEVALUE;
twCap.hContainer:= GlobalAlloc(GHND, sizeof(TW_ONEVALUE));
pOneVal:= pTW_ONEVALUE(GlobalLock(twCap.hContainer));
pOneVal.Item:= TW_UINT32(True);
pOneVal.ItemType:= TWTY_BOOL;
GlobalUnlock(twCap.hContainer);
L_TwainSetCapability(hTwnSession, @twCap, LTWAIN_CAPABILITY_SET);
L_TwainEndCapsNeg(hTwnSession);
end;

Franco