A program operator can have varying degrees of network management capability, depending on the options specified in its APPL definition statement. If you code AUTH=SPO (secondary program operator) or PPO (primary program operator), the application program can issue VTAM® operator commands (except START and HALT) using the SENDCMD and RCVCMD macro instructions. The application program can then monitor and control the VTAM domain.

An application program that you specify as a primary program operator (PPO) receives all unsolicited messages, that is, all informational and error messages that are not replies to operator commands. If no application program that is designated as PPO is active when these messages occur, they are directed to the system console.

An application program that you specify as a secondary program operator (SPO) can receive solicited messages, that is, messages that are in reply to VTAM operator commands issued by that program operator only. You can, however, limit the number of messages that can be queued for a program operator by using the POAQLIM operand on the APPL definition statement.