Telnet client users can sign on and run 5250 full-screen applications using 3270 full-screen mode.
The server negotiates 3270 full-screen support with any Telnet client application that supports 3270 full-screen applications, rather than 5250 full-screen applications. An example of a system that negotiates 3270 full-screen support is the IBM S/390® family.
Telnet 5250 (TN5250) delivers the data stream between the two systems as EBCDIC. Because the 3270 data streams are translated into 5250 data streams, the workstation devices operate as a remote 5251 display to the iSeries™ server and application programs.
After you have completed the general configuration of the Telnet server, there are a few additional steps to enable server support for 3270 full-screen mode. Full-screen mode is a "block" mode as opposed to a "line" mode. "Line" mode is when data transmits one line at a time, whereas "block" or full-screen mode transmits the whole screen at one time.
For information about supported 3270 device capabilities, refer to Supported 3270 terminal types.
For 3270 full screen considerations such as screen size, keyboard mapping, cursor select key, and error messages and null characters, see 3270 Telnet client sessions.
Complete the following tasks to configure the Telnet server for 3270 full-screen mode:
When the iSeries Telnet server automatically creates virtual display devices, it uses the QKBDTYPE system value to determine the keyboard type for the virtual device.
If the initial creation of the virtual device fails by using the QKBDTYPE system value, the Telnet server uses the keyboard value USB to try to create the device. If the second attempt to create the virtual display device fails using the value of USB, then a message (CPF87D7) is sent to the system operator message queue. This message indicates that the system cannot automatically select the virtual device.
A 3270 display station connected to an iSeries server using Telnet appears to be a 5251 display station to an iSeries server. The 3270 display station keyboard has a 5251-equivalent keyboard map associated with it, which allows it to complete 5251-equivalent functions on the iSeries server.
When a Telnet client system user first signs on in 3270 full-screen mode, the iSeries server automatically assigns the default keyboard map to the user's 3277, 3278, or 3279 keyboard. Avoid this by including a user-defined keyboard map in the user's profile sign-on procedure. This supplies the mapping needed for the 3270 keyboards to do most of the same functions as their 5250-equivalent keyboards do.
Use the Change Keyboard Map (CHGKBDMAP) command if you want to make minor changes to the default keyboard map. This command is available from the Configure TCP/IP Telnet menu as option 7 (Change 3270 keyboard map).
If you want to set a new keyboard map, use the Set Keyboard Map (SETKBDMAP) command. This command is option 7 (Change 3270 keyboard map) on the Configure TCP/IP Telnet menu. The key assignments that you specify are in effect until you use these commands again to specify new key assignments or until you sign off.
For more information about keyboard mapping see 3270 keyboard mapping for Telnet servers.
A message queue is like a mail box for messages. The iSeries server has several message queues that hold messages that provide helpful information when finding and reporting problems. When your workstation message queue is in break mode, messages appear on the 3270 device exactly as they appear on the 5250 display. To receive messages in break mode, you must specify *BREAK on the change message queue (CHGMSGQ) command. When your workstation is not in break mode, you receive the following message: A message has arrived on a message queue.
To retrieve this message and continue using the workstation, follow these steps:
When using an iSeries server from a 5250-type terminal, pressing certain keys in certain situations causes input to be inhibited. When this occurs, the 5250 terminal displays an input-inhibited light.
Two asterisks shown in the lower-right corner of the display indicate the input-inhibited light. When the keyboard is inhibited, any keys mapped to the iSeries function keys are ignored.
To reset the keyboard, press the Enter key, or press the key mapped to the iSeries Reset key.