Zero Length RU Causes a Blank Page to be Printed (170583)

The information in this article applies to:

Microsoft Host Integration Server 2000
Microsoft SNA Server 3.0
Microsoft SNA Server 3.0 SP1
Microsoft SNA Server 3.0 SP2
Microsoft SNA Server 3.0 SP3
Microsoft SNA Server 3.0 SP4
Microsoft SNA Server 4.0
Microsoft SNA Server 4.0 SP1
Microsoft SNA Server 4.0 SP2
Microsoft SNA Server 4.0 SP3
Microsoft Host Integration Server 2004

This article was previously published under Q170583

SYMPTOMS

When a zero-length RU is sent to the SNA print server as part of a host print job, a blank page will be printed. The following is an example of a zero-length RU as captured in a SNA Server Data Link Control Message trace:

   04160080->01020101 DLC DATA     
      DAF:EC OAF:01 ODAI:off Normal 
      RQE FMD BC EC DR1 PI BB EB 

   ---- Header  at address 01034418, 1 elements ----
   04B00004 00002C00 EC010004 01002102     <......,.......!.>

   ---- Element at address 0152D5A4, start 10, end 12 ----
   0391C0                                  <.j.             >

The Element portion of the preceding frame contains a Request Header (RH) of x'0391C0', but no actual data.

CAUSE

Print Server treats the zero-length RU as a unique print job where 0D 0C (CR FF) is sent to the printer. The print server calls "StartDoc" to start a new document as soon as it receives a request, and "EndDoc" when the document is complete. Even though there is no data submitted to the printer between the "StartDoc" and "EndDoc" calls, the printer will still print a form feed (FF).

RESOLUTION

There are two possible workarounds for this issue:

Configure the print session to use a PDF file. The PDF file uses "StartDocPrinter" and "EndDocPrinter" which do not automatically produce a FF. For instructions on configuring PDF files, refer to the SNA Server online help Chapter 6 Printer Definition Files.

-OR-
Use the DelayPrintStart Registry parameter as discussed in the following Microsoft Knowledge Base article:
172283 Title: Blank Page Is Printed Between Each Print Job

Modification Type:	Major	Last Reviewed:	3/17/2005
Keywords:	kbprb KB170583