TCAM Considerations

This appendix describes considerations that apply to DC sessions initiated from terminals on TCAM lines (that is, lines defined as TYPE IS TCAMLIN).

Initial Task Execution

You can define a DC/UCF task to be executed whenever a user initiates a DC/UCF session on a TCAM line. You can use the task to invoke a program such as the signon program (RHDCSNON), CA ADS runtime system (ADSORUN1), or a user defined map.

The DC/UCF task code must match the TCAM Message Control Program (MCP) application id that the user enters to initiate the DC/UCF session. Additionally, the DC/UCF task must be defined with the INPUT parameter.

For example, assume the TCAM MCP application id used to initiate a DC/UCF session is IDMS. If you include the following TASK statement in the DC/UCF system definition, the signon program is invoked automatically whenever a user initiates a session on a TCAM line:

ADD TASK IDMS
    INVOKES PROGRAM RHDCSNON
    INPUT

Disconnect Messages

DC/UCF issues either of two messages when it wants to terminate a session on a TCAM line:

DC080101 LOGOFF - DISCONNECTED FROM IDMS-DC
IDMS-DC/UCF issues this message when:
- The terminal operator executes the BYE task.
- The resource timeout interval for the terminal expires.
- A user at another terminal issues a DCMT VARY PTERM DISCONNECT or VARY PTERM OFFLINE command for the terminal.
DC080102 LOGOFF - NO AVAILABLE IDMS-DC PTERMS
DC/UCF issues this message when a user attempts to initiate a session but all of the TCAM physical terminals are either in use, reserved for other terminals, or offline.

DC/UCF sends the message to the terminal from which the session was initiated. In the case of message DC080101, DC/UCF also disconnects the terminal from the physical terminal element (PTE).

You should write the TCAM MCP to scan for messages DC080101 and DC080102 in the output message handler. The TCAM MCP should terminate the DC/UCF session when the message handler detects either message.