3494 library error codes

[David E Ehresman]

I'm getting message:
  ANR8301E I/O error on library 3494 (OP=004C6D32, SENSE=N/A,
CC=00000000). (SESSION: 470264)
Any idea what that OP code is and where they are documented?

3494 library on TSM 5.2.3.1 running on AIX 5.1 64 bit