IBM TN3270E Emulator Cannot Log On to Host After You Press SYSREQ (810174)


The information in this article applies to:

  • Microsoft SNA Server 4.0
  • Microsoft SNA Server 4.0 SP1
  • Microsoft SNA Server 4.0 SP2
  • Microsoft SNA Server 4.0 SP3
  • Microsoft SNA Server 4.0 SP4
  • Microsoft Host Integration Server 2000
  • Microsoft Host Integration Server 2000 SP1

SYMPTOMS

You cannot log on to the host when you use IBM Personal Communications for TN3270E communication if a MSG10 Message is not received during the activation of the logical unit (LU).

For additional information about a similar issue when using the 3270 Client in TN3270E mode included with SNA Server 4.0 and Host Integration Server 2000, click the following article number to view the article in the Microsoft Knowledge Base:

327027 TN3270E Client Cannot Log on Unless Host Sends MSG10 Message

The following event may be logged in the Application Event Log on the SNA Server or Host Integration Server 2000 system that is running the TN3270 server: Event ID: 306
Source: TN3270 Server
Description: Input from the client TCP/IP Address (port TCP/IP port) using LU LU Name was ignored.
Explanation: Data arrived from the client at a time when it could not be processed or queued for transmission to the host.
Note: This problem may also occur with other TN3270E emulators.

CAUSE

The TN3270 server enters an unowned state when it receives a SYSREQ (System Request) from a TN3270E client. While the TN3270 server is in an unowned state, it ignores SSCP_LU_DATA data that follows the SYSREQ.

RESOLUTION

Service pack information

To resolve this problem, obtain the latest service pack for Microsoft Host Integration Server 2000. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

328152 How to obtain the latest service pack for Host Integration Server 2000

Hotfix information

The English version of this fix has the file attributes (or later) that are listed in the following table. The dates and times for these files are listed in coordinated universal time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time tool in Control Panel.

DateTimeVersionSize File name
08-Nov-200217:535.0.0.900250,128Tn3servr.exe

STATUS

SNA Server 4.0

Microsoft has confirmed that this is a problem in Microsoft SNA Server versions 4.0, 4.0 SP1, 4.0 SP2, 4.0 SP3, 4.0 SP4.

Host Integration Server 2000

Microsoft has confirmed that this is a problem in Microsoft Host Integration Server 2000 and Host Integration Server 2000 SP1 . This problem was corrected in Microsoft Host Integration Server 2000 Service Pack 2.

MORE INFORMATION

In many IBM mainframe environments, the virtual telecommunications access method (VTAM) is configured to allow unformatted system services (USS) messages to be sent to 3270 devices, including 3270 emulators. One of the most common USS messages is the USS MSG10 message, which is also known as the VTAM sign-on, greeting, or banner screen.

If configured, the MSG10 message is sent to a 3270 LU when the LU is activated and when a SSCP-LU (System Services Control Point - Logical Unit) session is active. A MSG10 message typically contains some general information about the mainframe system, a list of applications, and a place to enter the name of the application to connect to.

In those environments that do not use a MSG10 message, the user must enter an unformatted logon string to actually connect to an application on the host system. The following is an example of an unformatted logon string that is used to connect to an application called CICS01: 
logon applid=cics01
The TN3270E RFC does not specifically address how to handle unformatted logons. The vendors that provide TN3270E servers and emulators decide how to handle unformatted logons. To read about the TN3270 enhancements, please refer to the TN3270E RFC:
http://www.faqs.org/rfcs/rfc2355.html
The IBM Personal Communications TN3270E emulator requires that the user press the SYSREQ key to allow user input if the host system does not send a MSG10 screen when the 3270 LU is activated. After pressing SYSREQ, the user can enter data , such as an unformatted logon string to logon to the host application. If the IBM Personal Communications TN3270E emulator is connecting to the TN3270 server that is included with SNA Server 4.0 or Host Integration Server 2000, the unformatted logon string is not sent to the host application because of the problem described earlier in this article.

After applying the update, the TN3270 server will send any data it receives from the TN3270E emulator following a SYSREQ to the host system. If the data is an unformatted logon string, the user will be able to logon to the host application.

Idea Section

IBM TN3270E Emulator Unable to Logon to Host After Pressing SYSREQ
Modification Type:MinorLast Reviewed:9/27/2005
Keywords:kbHotfixServer kbQFE kbQFE kbprb kbhis2000fix KB810174
©2004 Microsoft Corporation. All rights reserved.