Get printer status before printing

[mmans]

Hi,

I have to watch the printer status of a matrix printer (Epson LQ1070+). Therefore I used the WMI class 'Win32_Printer'. But I only get a status (eq. Out of paper) when I am trying to print. When no print job is in the spooler I always get the status 'READY/IDLE', even when the printer got no paper and the red 'Out of paper' LED on the printer is ON.

Does anyone know how I can get a status before I send a printjob?

I heard that it's also possible to read the LPT-port directly. As I read obn a webpage, a couple of pins from the printerconnector are also sending a status. But I'm using win NT4, and I don't know how I have to read the LPT-port directly.

Can somebody give me an example-code on how to read the LPT port?


Thanx for your help!

[Hack]

This should tell you just about anything you need to know about your printer. Associated Links:
http://www.merrioncomputing.com/Prog...rintStatus.htm
http://www.merrioncomputing.com/Prog...g/PrintJob.htm

Private Const NULLPTR = 0&
' Constants for DEVMODE
Private Const CCHDEVICENAME = 32
Private Const CCHFORMNAME = 32
' Constants for DocumentProperties
Private Const DM_MODIFY = 8
Private Const DM_COPY = 2
Private Const DM_IN_BUFFER = DM_MODIFY
Private Const DM_OUT_BUFFER = DM_COPY
' Constants for dmOrientation
Private Const DMORIENT_PORTRAIT = 1
Private Const DMORIENT_LANDSCAPE = 2
' Constants for dmPrintQuality
Private Const DMRES_DRAFT = (-1)
Private Const DMRES_HIGH = (-4)
Private Const DMRES_LOW = (-2)
Private Const DMRES_MEDIUM = (-3)
' Constants for dmTTOption
Private Const DMTT_BITMAP = 1
Private Const DMTT_DOWNLOAD = 2
Private Const DMTT_DOWNLOAD_OUTLINE = 4
Private Const DMTT_SUBDEV = 3
' Constants for dmColor
Private Const DMCOLOR_COLOR = 2
Private Const DMCOLOR_MONOCHROME = 1
 
Private Type DEVMODE
    dmDeviceName(1 To CCHDEVICENAME) As Byte
    dmSpecVersion As Integer
    dmDriverVersion As Integer
    dmSize As Integer
    dmDriverExtra As Integer
    dmFields As Long
    dmOrientation As Integer
    dmPaperSize As Integer
    dmPaperLength As Integer
    dmPaperWidth As Integer
    dmScale As Integer
    dmCopies As Integer
    dmDefaultSource As Integer
    dmPrintQuality As Integer
    dmColor As Integer
    dmDuplex As Integer
    dmYResolution As Integer
    dmTTOption As Integer
    dmCollate As Integer
    dmFormName(1 To CCHFORMNAME) As Byte
    dmUnusedPadding As Integer
    dmBitsPerPel As Integer
    dmPelsWidth As Long
    dmPelsHeight As Long
    dmDisplayFlags As Long
    dmDisplayFrequency As Long
End Type
 
Private Declare Function OpenPrinter Lib "winspool.drv" Alias "OpenPrinterA" (ByVal pPrinterName As String, phPrinter As Long, ByVal pDefault As Long) As Long
Private Declare Function DocumentProperties Lib "winspool.drv" Alias "DocumentPropertiesA" (ByVal hwnd As Long, ByVal hPrinter As Long, ByVal pDeviceName As String, pDevModeOutput As Any, pDevModeInput As Any, ByVal fMode As Long) As Long
Private Declare Function ClosePrinter Lib "winspool.drv" (ByVal hPrinter As Long) As Long
Private Declare Sub CopyMemory Lib "KERNEL32" Alias "RtlMoveMemory" (hpvDest As Any, hpvSource As Any, ByVal cbCopy As Long)
 
 
Private Function StripNulls(OriginalStr As String) As String
    If (InStr(OriginalStr, Chr(0)) > 0) Then
        OriginalStr = Left(OriginalStr, InStr(OriginalStr, Chr(0)) - 1)
    End If
    StripNulls = Trim(OriginalStr)
End Function
 
Private Function ByteToString(ByteArray() As Byte) As String
    Dim TempStr As String
    Dim I As Integer
 
    For I = 1 To CCHDEVICENAME
        TempStr = TempStr & Chr(ByteArray(I))
    Next I
    ByteToString = StripNulls(TempStr)
End Function
 
Private Function GetPrinterSettings(szPrinterName As String, hdc As Long) _
            As Boolean
    Dim hPrinter As Long
    Dim nSize As Long
    Dim pDevMode As DEVMODE
    Dim aDevMode() As Byte
    Dim TempStr As String
 
    If OpenPrinter(szPrinterName, hPrinter, NULLPTR) Then
        nSize = DocumentProperties(NULLPTR, hPrinter, szPrinterName, _
                NULLPTR, NULLPTR, 0)
        ReDim aDevMode(1 To nSize)
        nSize = DocumentProperties(NULLPTR, hPrinter, szPrinterName, _
                aDevMode(1), NULLPTR, DM_OUT_BUFFER)
        Call CopyMemory(pDevMode, aDevMode(1), Len(pDevMode))
 
        List1.Clear   ' empty the ListBox
        List1.AddItem "Printer Name: " & _
                ByteToString(pDevMode.dmDeviceName)
 
        If pDevMode.dmOrientation = DMORIENT_PORTRAIT Then
            TempStr = "PORTRAIT"
        ElseIf pDevMode.dmOrientation = DMORIENT_LANDSCAPE Then
            TempStr = "LANDSCAPE"
        Else
            TempStr = "UNDEFINED"
        End If
        List1.AddItem "Orientation: " & TempStr
 
        Select Case pDevMode.dmPrintQuality
            Case DMRES_DRAFT
                TempStr = "DRAFT"
            Case DMRES_HIGH
                TempStr = "HIGH"
            Case DMRES_LOW
                TempStr = "LOW"
            Case DMRES_MEDIUM
                TempStr = "MEDIUM"
            Case Else   ' positive value
                TempStr = CStr(pDevMode.dmPrintQuality) & " dpi"
        End Select
        List1.AddItem "Print Quality: " & TempStr
 
        Select Case pDevMode.dmTTOption
            Case DMTT_BITMAP    ' default for dot-matrix printers
                TempStr = "TrueType fonts as graphics"
            Case DMTT_DOWNLOAD  ' default for HP printers that use PCL
                TempStr = "Downloads TrueType fonts as soft fonts"
            Case DMTT_SUBDEV    ' default for PostScript printers
                TempStr = "Substitute device fonts for TrueType fonts"
            Case Else
                TempStr = "UNDEFINED"
        End Select
        List1.AddItem "TrueType Option: " & TempStr
 
        ' Windows NT drivers often return COLOR from Monochrome printers
        If pDevMode.dmColor = DMCOLOR_MONOCHROME Then
            TempStr = "MONOCHROME"
        ElseIf pDevMode.dmColor = DMCOLOR_COLOR Then
            TempStr = "COLOR"
        Else
            TempStr = "UNDEFINED"
        End If
        List1.AddItem "Color or Monochrome: " & TempStr
 
        If pDevMode.dmScale = 0 Then
            TempStr = "NONE"
        Else
            TempStr = CStr(pDevMode.dmScale)
        End If
        List1.AddItem "Scale Factor: " & TempStr
 
        List1.AddItem "Y Resolution: " & pDevMode.dmYResolution & " dpi"
        List1.AddItem "Copies: " & CStr(pDevMode.dmCopies)
        ' Add any other items of interest ...
 
        Call ClosePrinter(hPrinter)
        GetPrinterSettings = True
    Else
        GetPrinterSettings = False
    End If
End Function
 
'Add A Listbox, or someother type of display control
'For detailed information about your printer, place the following
'code in the click event of something
If GetPrinterSettings(Printer.DeviceName, Printer.hdc) = False Then
   List1.AddItem "No Settings Retrieved!"
End If

[mmans]

Thanks for the code Hack!

I tried it, but I get the same result. I can only read the status
from the document that is currently processed.

Do you know something about reading the parallel port directly?

Greetz,

M.Mans

[Hack]

Try searching these sites:

http://www.msdn.microsoft.com/
http://www.codehound.com/

[MerrionComputin]

The OpenPrinter() and GetPrinter() API calls return the values for the printer status that they get from the printer driver itself.

In many cases (for non BIDI interface type printers) the only way that the printer driver knows that there is a problem with the printer is when a job stalls so for such printer drivers it is not possible to know the status of the printer before a job is sent to it.

HTH,
Duncan