Last Modified: Aug 19, 2026
Affected Product(s):
BIG-IP TMOS
Known Affected Versions:
12.1.0, 12.1.0 hf1, 12.1.0 hf2, 12.1.1, 12.1.1 hf1, 12.1.1 hf2, 12.1.2, 12.1.2 hf1, 12.1.2 hf2, 12.1.3, 12.1.3.1, 12.1.3.2, 12.1.3.3, 12.1.3.4, 12.1.3.5, 12.1.3.6, 12.1.3.7, 12.1.4, 12.1.4.1, 12.1.5, 12.1.5.1, 12.1.5.2, 12.1.5.3, 12.1.6
Opened: May 05, 2016 Severity: 3-Major
If the fan tray is removed from a VIPRION C2xxx-series chassis (C2400, C2200), errors similar to the following may be logged in the LTM log: err chmand[5862]: 012a0003:3: getSensorData: sensor read fault for Chassis XXXXXXXX, LOP return code 2 : File sensor/LopSensSvc.cpp Line 2315 Where 'XXXXXXXX' is the name of a Chassis sensor object.
No functional impact. These errors indicate that the Backplane Micro-Controller (BµC or 'BuC') is not responding to the periodic sensor reading requests from TMOS. In VIPRION C2xxx-series chassis, the Backplane Micro-Controller is physically located in the fan tray. When the fan tray is removed, the Backplane Micro-Controller cannot respond to these requests.
This may occur with VIPRION C2xxx-series chassis: C2400, C2200
Ignore errors reading Chassis sensors logged while the fan tray is not present.
None