3270 terminal programmed symbols

Programmed symbols (PSs), an optional feature of the 3270 terminal, allow storage and access of up to six sets of 190 characters, each of which can be user-defined and loaded by the program. You can load PS buffers with either a VTAM® application or a user-defined procedure. After the PS buffers are loaded, you can use them on a field-by-field basis on the screens formatted by the Message Format Service (MFS).

If a hardware error occurs while you are loading a PS buffer, IMS:

  1. Returns the message used to load the PSs to the IMS message queue.
  2. Takes the terminal out of service (except for SLU-2 devices).
  3. Logs the error to the IMS log.
  4. Sends a message to the IMS master terminal.

After you correct the hardware error and the terminal is in service, IMS re-sends the message used to load the PSs.

If the PS load function failed because of an error in the message used to load them:

  1. Use the /DEQUEUE command to dequeue the message. You might have to enter the /DEQUEUE command from the master terminal.
  2. Correct the error.
  3. Reenter the transaction to send the message to reload the PSs.

For SLU-2 devices, if you have not loaded the PS buffers and IMS sends a message requiring the use of a PS buffer, the 3270 terminal rejects the message and IMS:

  1. Returns the invalid message to the IMS queue.
  2. Logs the error to the IMS log.
  3. Sends a DFS2078I message to the node, telling you that the output was rejected. However, if the message being rejected is in storage, IMS sends the DFS2078I message to the IMS master terminal and closes the node.

IMS leaves the terminal in protected mode after it receives the DFS2078I message.