VTAM commands and indicators used with SLU P
VTAM® commands and indicators (communication control information) are necessary for data transmission between an IMS application program and another VTAM logical unit.
The following table shows which VTAM commands and indicators IMS sends to and receives from the SLU P controller. Results are unpredictable if any unsupported commands or indicators are used.
With the exception of the request-recovery command and the change-direction indicator, which are described following the table, the commands and indicators operate as described in z/OS® Communications Server: SNA Programming.
Recommendation: During a SLU P session, every
input message must have either a change-direction (CD) or end-bracket
(EB); otherwise, the session is terminated.
| VTAM command/indicator | IMS sends to controller | IMS receives from controller |
|---|---|---|
| INDEPENDENT OF SESSION | ||
| Initiate Session | X | |
| Procedure Error | X | |
| Terminate Session | X | |
| SESSION CONTROL | ||
| Bind | X | |
| Clear | X | |
| Request-Recovery (RQR) | X | |
| Set-and-Test-Sequence Numbers (STSN) | X | |
| Start Data Traffic (SDT) | X | |
| Unbind | X | |
| NORMAL (synchronous) FLOW | ||
| Begin-Bracket (BB) | X | X |
| BID | X | |
| CANCEL | X | X |
| CHASE | X | |
| End-Bracket (EB) | X | X |
| Logical Unit Status (LUS) | X | |
| Quiesce Complete (QC) | X | |
| Ready-to-Receive (RTR) | X | |
| Change Direction (CD) | X | |
| EXPEDITED (asynchronous) FLOW | X | |
| Quiesce-at-end-of-chain (QEC) | X | |
| Release Quiesce (RELQ) | X | |
| Request-Shutdown (RSHUTD) | X | |
| Shutdown (SHUTD) | X | |
| Shutdown Complete (SHUTC) | X | |
| Signal | X |