Changing the 3270 Attention and System Request Keys

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In 3270 terminal emulation, the 3270 attention and system request functions send telnet command strings to the host computer. By default, the telnet command strings are defined as follows:

Key Telnet Command String        
TN3270        TN3270E        
AttentionFFF3        FFF4        
System RequestFFF4        FFF5        

 

In rare instances, the default setting may not work with your host computer. In this case, you may change the command string sent by either of these keys. You can do this for all sessions by adding a registry entry or for a specific session by adding a line to the session profile. TN3270 Plus searches for the telnet command strings in the following order:

 

1.Session profile
2.Registry
3.Default setting

 

Adding a Registry Entry

Use this method to change the telnet command string for all sessions that do not have a value set in the session profile. To specify a new telnet command string, use the following steps:

 

1.Back up the registry. You should always back up the registry before making modifications.

 

2.Run regedit.exe

 

3.Navigate through the following keys and folders: HKEY_CURRENT_USER\Software\SDI\TN3270 Plus

 

4.Right click on the TN3270 Plus folder and select New from the popup menu and Key from the second level popup menu.

 

5.A key name of New Value #1 is created. Replace New Value #1 with 3270 and press enter.

 

6.Right click on the 3270 folder and select New from the popup menu. Select String Value from the second level popup menu.

 

7.A key name of New Value #1 is created. Replace New Value #1 with AttnKeyString or SysreqKeyString and press enter.

 

8.Right click on the newly created value and select Modify from the popup menu.

 

9. In the Edit String dialog box, enter the telnet command string into the Value data edit box and click the OK button.

 

Adding a Session Profile Entry

Use this method to change the telnet command string for a specific session. The session profile file name is the session name with the .tsp extension. For example, if your session name is "IBM Mainframe" the corresponding session profile name is "IBM Mainframe.tsp." To add the telnet command string entry:

 

1.Edit the session profile with notepad.exe or another word processor.

 

2.Add the following line(s) to the end of the session profile:

AttnKeyString=xxxx

SysreqKeyString=xxxx

 

Where:

xxxxis the telnet command string. The string must be a hexadecimal value.        
3.Save the updated session profile and restart TN3270 Plus.

 

TN3270 Plus is continually being improved. To learn more about the latest enhancements, please review our Version History web page.