Solving programmed symbol load problems

Once the hardware error is corrected and the terminal is in service, the programmed symbol load message is re-sent.

If the programmed symbol load failed because of an error in the programmed symbol load message, the operator must:

1. Dequeue (/DEQ) the message (the master terminal operator might have to issue the /DEQ command).
2. Correct the error.
3. Reenter the transaction to send the programmed symbol load message again.

If a method is available for informing the next user of the programmed symbol buffer status, then the terminals with loaded programmed symbol buffers should not be turned off. When a power failure occurs, or a terminal is turned off, the contents of the programmed symbol buffers are lost.

When a terminal is turned on and no IMS messages are waiting to be sent to the display, load all required programmed symbol buffers using an IMS transaction (or some non-IMS method). However, if IMS messages are waiting to be sent, and these messages require the use of one or more programmed symbol buffers, the sending of the queued messages must be delayed until the programmed symbol buffers can be reloaded. This can be accomplished using response mode transactions to load the programmed symbol buffers.

If the programmed symbol buffers are not loaded and a message that requires a programmed symbol buffer is sent to the terminal, the following actions take place:

• For non-SLU 2 devices, IMS takes the terminal out of service, sends a message to the master terminal, and returns the output message to the message queue.
• For SLU 2 devices, the message is rejected and a sense code is returned to IMS. IMS then:
  • Returns the invalid message to the IMS queue.
  • Logs the error to the IMS log.
  • Sends an error message to the IMS master terminal if the output was a response mode reply, and takes the terminal out of service. If it is not in response mode, the error message is sent to the terminal and it is left in protected mode.

If the user-written application program is designed to queue an unsolicited message requiring a particular programmed symbol load buffer to an LTERM, the first part of the message could include a load programmed symbol data stream; however, this message could not be processed by MFS.

When a message is waiting on the IMS queue for a terminal and requires a programmed symbol that is not loaded, perform one of the following:

• If the terminal is attached by VTAM®, load the programmed symbol buffers using a VTAM application.
• If a queued message requires a programmed symbol buffer and it is normal user output (for example, the output is not response mode or conversational), then the use of a response mode transaction to load the programmed symbol buffer permits the queued message to be properly displayed. If loading the buffers requires multiple messages, multiple response mode transactions can be used.
• Dequeue (/DEQ) the message (or have the master terminal operator dequeue the message) requiring use of a programmed symbol buffer; enter a transaction to load the programmed symbol buffer required; and then reenter the transaction that originally generated the queued message.
• Temporarily assign the LTERM to which the message is queued to another physical terminal. Load the programmed symbol buffer, then reassign the LTERM to the original physical terminal. The LTERM must be assigned to a terminal that will not cause a message to be sent (as, for example, a 3270 display or SLUTYPE2 that is in protected screen mode).