TN3270 SSCP-LU Sessions Send x'40' Instead of Null RU

ID: Q172816

The information in this article applies to:

Microsoft SNA Server, versions 3.0, 3.0 SP1

IMPORTANT: This article contains information about editing the registry. Before you edit the registry, make sure you understand how to restore it if a problem occurs. For information about how to do this, view the "Restoring the Registry" Help topic in Regedit.exe or the "Restoring a Registry Key" Help topic in Regedt32.exe.

SYMPTOMS

The SNA TN3270 Server will send an x'40' character (space) instead of a Null RU when you press the ENTER key on an SSCP screen. When this occurs, the TN3270 Client will receive the error message:

Function not supported.

CAUSE

A previous change to the TN3270 Server component caused an x'40 character, instead of an x'7d', to be sent as a null character when you press the Enter key during an SSCP-LU session. The x'40 causes the Host to send back an -RSP after a DLC Data RQD is sent.

STATUS

Microsoft has confirmed this to be a problem in SNA Server versions 3.0 and 3.0 Service Pack 1 (SP1). This problem was corrected in the latest SNA Server version 3.0 U.S. Service Pack. For information on obtaining this Service Pack, query on the following word in the Microsoft Knowledge Base (without the spaces):


   S E R V P A C K

MORE INFORMATION

With the fix applied, Tn3servr.exe sends a Null RU to the host by default. If you need the x'40' character, you can modify the registry as shown below.

WARNING: Using Registry Editor incorrectly can cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk.

For information about how to edit the registry, view the "Changing Keys and Values" Help topic in Registry Editor (Regedit.exe) or the "Add and Delete Information in the Registry" and "Edit Registry Data" Help topics in Regedt32.exe. Note that you should back up the registry before you edit it. If you are running Windows NT, you should also update your Emergency Repair Disk (ERD).

Start Registry Editor (Regedt32.exe or Regedit.exe, as appropriate for your version of Windows NT).

Go to the following key in the registry:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\TN3270\Parameters

On the Edit menu, click Add Value, and use the following entry:

Value Name: ReplaceNullRUs
Data Type: REG_SZ
Value: YES

Exit Registry Editor.

Additional query words:

Keywords : kbnetwork snatn3270 kbfix3.00.sp2
Version : WINDOWS:3.0,3.0 SP1
Platform : WINDOWS
Issue type : kbbug