VTAM logical unit status (LUSTATUS) command

If the SLU P system detects a component-down or workstation-down condition, and the SLU P system is not currently receiving a message from IMS, it can send the VTAM® LUSTATUS command to notify IMS of the condition.

Four bytes of data, identical in format to the exception DR1 or DR2 for STATION/COMPONENT DOWN, must accompany the LUSTATUS. When IMS receives the LUSTATUS, it marks the indicated component inoperable or terminates the session.

The workstation can also notify IMS when the component is operable by sending the VTAM LUSTATUS. The system sense field must equal X'0001', and the user sense field byte 3 must equal a value from X'01' through X'04'. IMS resets the inoperable condition for the indicated component and sends any output queued for it.

All other values for LUSTATUS are considered requests to terminate the session.