How the VTAM I/O facility affects your VTAM terminal

VTAM® terminals can fail to respond to requests sent by IMS. The master terminal operator or an automated operator interface application program can optionally activate a timeout facility. This allows a message stating a specific amount of time has passed to be sent to the master terminal operator.

IMS TM can be set up to do one of the following:

• Do nothing, which means that your terminal remains inactive. This is the default.
• Send a message to the master terminal operator stating that the specified period of time has passed. The operator can then determine what action, if any, should be taken.
• Send a message to the master terminal operator stating that the specified period of time has passed. IMS TM then issues the VTAM VARY NET, INACT command followed by a VTAM VARY NET, ACT command. If the terminal is defined to IMS TM as non-shared and operable, and if IMS TM is not shutting down, IMS TM issues an OPNDST for the terminal.
  Restriction: This option does not apply to ISC terminals. If your installation chooses this option and an ISC terminal times out, a message is sent to the master terminal stating that the specified period of time has passed. The operator can determine what action, if any, should be taken.