- Entry:
- XID
- VIT option:
- CIA
- Event:
- Exchange ID (Part 1)
- VIT processing module:
- ISTRACCI
- Control is returned to:
- ISTTSCCU or ISTTSC8X
This trace record contains information about inbound or
outbound exchange ID processing. 
- Byte (hex)
- Contents
- 00–03
- Record ID:
- C"XIDI" for inbound XID
- C"XIDO" for outbound XID
- 04–07
- NCB address
- 08–0B
- Boundary physical unit block (BPB) address or 0
- 0C–1F
- 20 bytes of XID data