Asynchronous output to a valid destination
You can send asynchronous output (such as inserts, broadcasts, and message switches) only after enabling ETO and defining a valid ETO descriptor and a valid destination LTERM name.
ETO is enabled by specifying ETO=Y in the IMS or DCC startup procedure.
The ETO descriptor is used for creating a user structure.
If control blocks exist for a previously created user structure and LTERM, the control blocks are reused.