Sends a message to the query driver.

──┬─ QD ────┬─ SCODE ── [<query number>] ──────────────────────────────┤
  ├─ DUMP ──┤
  └─ QUERY ─┘

The QD command generates a dump of the query symbolic or the Scode. The information is stored in a file named QDUMP/<mix number>/<serial number>.