- Entry:
- IDXI or IDXO
- VIT option:
- CIA
- Event:
- Identification Exchange (Part 1)
- VIT processing module:
- ISTRACCI
- Control is returned to:
- ISTLLCXI or ISTLLCXR
This trace record contains information about inbound or
outbound identification exchange processing. 
- Byte (hex)
- Contents
- 00–03
- Record ID:
- C"IDXI" for inbound IDX
- C"IDXO" for outbound IDX
- 04
- ID is the primary address space ID (ASID). This field is 0 if the ASID is greater than X'FF'.
- 05–07
- 0
- 08–0B
- Channel Unit Address
- 0C–0F
- NCB address
- 10–17
- Block header
- 18–1B
- 0
- 1C–1F
- Request parameter header (RPH) address