Hi, 

it always help to see some code snippet to better understand how you use the objectXMFdisplay dll.

But let me try to answer:
RUMBA consist of a number of different Controls.
You're already using the objectXMFdisplay that contains the 3270 protocol processor and other important services.

The Capture Screen command is part of the OBJECTX Application Print/Paste Control.

Syntax:

<object>.CaptureScreen(FileName As String)

code snippet:

Private Sub MnuCapture_Click()
  'Procedure captures the current screen and attempts to write it to file
  'Call the CaptureScreen method
 ObjectXPrintPaste1.CaptureScreen ("")
End Sub

You can build your own CaptureScreen Method by using GetScreen

Pseudocode

//read entire Model 2 host screen into sBuffer as a stream
sBuffer = ObjectXRumbaControl.GetScreen(1,1,1920)
//divide into 80 char lines by inserting CRLF at end of each line
sBuffer1 = "";
for (i = 1 ; i <= 24; i )

 sBuffer1 = sBuffer1 sBuffer.substr((i * 80) - 79, 80) "CRLF";

then write sBuffer1 to a file

hope it helps

aescudero