IBM i 830 Repair Manual page 277

Reference Description/Action Perform all actions before exchanging
Code Failing Items
6984 High Speed Link (HSL) loop status message.
An HSL I/O loop has switched to its alternate path. This is an
informational SRC only.
Word 7 of the SRC contains the loop number in the leftmost 4
digits. The loop number is in hexadecimal format. You must
convert the hexadecimal loop number into decimal format to
recognize the loop number in HSM.
This SRC can be caused by a tower on the HSL loop powering
off.
This SRC may also appear in the SAL with a B600 6982 or B600
6981 logged at approximately the same time. In that case the
other SRC is reporting a failure and this SRC is reporting that
the alternate HSL path is now being used. Service the other
SRC if present, otherwise ignore this SRC.
B6xx (including A6xx)
Failing Item Location
Chapter 2. Unit Reference Codes
263