Return code posting

VTAM® posts return code information in registers 0 and 15, and in certain fields of the request's RPL. These fields are referred to as feedback fields. The manner in which registers 0 and 15 and the feedback fields are posted depends on whether synchronous request handling, asynchronous request handling with an ECB, or asynchronous request handling with an RPL exit routine is used.

Organizing an application program, provides an overview of these modes of operation. Handling errors and special conditions describes the way that VTAM and the application program handle RPL-based macroinstruction errors and special conditions. This appendix lists the RTNCD and FDB2 feedback field values that are set when those conditions arise.

Note: RTNCD and FDB2 designate RPL DSECT fields (and are not RPL operands). The RPL DSECT label for RTNCD is RPLRTNCD, and the label for FDB2 is RPLFDB2. Because of the similarity in spelling between these fields and label designations and others found in the RPL, refer to Table 1, Figure 1, and Figure 2 to avoid misinterpreting or incorrectly designating field names. The FDBK2 parameter on the SHOWCB and TESTCB macroinstructions represents the RPLFDB2 field.

Figure 1, Figure 2, and Figure 3 show the RTNCD,FDB2 combinations that are valid for each macroinstruction. Only the RPL-based macroinstructions are included because feedback posting applies only to RPL-based macroinstructions. CHECK and EXECRPL are not shown because all of the indicated RTNCD,FDB2 combinations are possible upon return from them.

Although specific error return codes apply only when RTNCD contains a recovery action code that is not 0, Figure 1, Figure 2, and Figure 3 include some FDB2 values for RTNCD=0. These are additional information codes that apply to certain normally completing requests. These codes are explained in the section following Figure 1, Figure 2, and Figure 3.

After you have used Figure 1, Figure 2, and Figure 3 to determine which RTNCD,FDB2 combinations are possible for a particular macroinstruction, refer to the return code descriptions for an explanation of each RTNCD,FDB2 combination.

Figure 1. RTNCD,FDB2 combinations possible for each macroinstruction (Part 1 of 3)

The diagram shows the RTNCD,FDB2 combinations that are valid for each macroinstruction. Only the RPL-based macroinstructions are included.

Figure 2. RTNCD,FDB2 combinations possible for each macroinstruction (Part 2 of 3)

Figure 3. RTNCD,FDB2 combinations possible for each macroinstruction (Part 3 of 3)

Should you detect a return code during program execution other than one described in this appendix, stop session communication. You can use SHOWCB macroinstructions to extract the contents of the RPL fields. You should then obtain a program dump. Save your source listings and any program execution output for IBM® program service representatives.