This write-only object triggers diagnostic actions on a PCM control block: writing 1 does nothing, writing 2 displays link looping information and timing statistics, and writing 3 clears those statistics. Admins use it as a maintenance command to inspect or reset low-level loop diagnostics on a voice link during troubleshooting. For example, a technician investigating suspected loopback issues would write the value 2 to pcmDebugLoopInfo to have the device report current looping information and timings.