This object indicates the status of the air flow. The fans' air flow direction must match the system's air flow direction to form an integrated air flow. For example: In DXS-3600, the normal fans' air flow direction must match the power fan's air flow direction. The power fan blow the cold air from outside to inside, all the normal fans must blow the hot air from inside to outside. Or the power fan blow the hot air from inside to outside, all the normal fans must blow the cold air from outside to inside. If one or more fans' air flow direction does not match the system's air flow direction, it will form an abnormal air flow. Then this log message will be triggered. ok(1) : A recover event indicates the air flow back to normal. abnormal(2): An alarm event indicates the air flow detects abnormal.