OSCaR Command Syntax

Purpose

OPEN, SEND, CLOSE, and RECEIVE (OSCaR) commands are an interface between mainframe CA ADS dialogs. OSCaR commands run as APPC commands; that is, as LU6.2 between mainframes. If a mainframe application is accessing a remote data base rather than a remote application, DDS should be more efficient.

Concept

OSCaR commands are much simpler than the CA IDMS SEND/RECEIVE verb set for APPC cooperative processing in that they provide only a subset of the complete APPC functionality and synchronization of conversation states is automatic. It is not necessary to understand the CA IDMS SEND/RECEIVE verb set, the IBM APPC verb set, or Conversation States before using OSCaR commands. However, it is necessary to understand basic cooperative processing concepts.

Coding Considerations

Only four commands are defined: OPEN, SEND, CLOSE, and RECEIVE
APPC and OSCaR commands are mutually exclusive within a single dialog:
- APPC verbs such as ALLOCATE, CONTROL SESSION, and SEND-DATA are not allowed in dialogs containing OSCaR verbs
- The four OSCaR verbs are not allowed in dialogs containing APPC verbs
APPC data areas WHAT-RECEIVED and REQUEST-TO-SEND-RECEIVED cannot be referenced in a dialog that contains OSCaR commands
OSCaR has no parameters equivalent to the FORMAT or SYNC-LEVEL parameters on the APPC ALLOCATE command
OSCaR verbs always run as NOFORMAT
Confirmation of user-validated data content must be sent via a user-defined control record rather than as a separate CONFIRM or SEND-ERROR command
Commands to perform synchronization of conversation states, (RECEIVE-AND-WAIT, PREPARE-TO-RECEIVE, and REQUEST-TO-SEND) are done automatically by the runtime system when needed. These commands are needed only when a command is issued and the line is in the wrong state.

Error conditions can be detected with autostatus or by examining ERROR-STATUS for 6901 or APPCCODE for a negative value.

More information:

Cooperative Processing Commands

Understanding Conversation States