  A real time Wall Monitoring System (WMS) is used on the WEST tokamak during
the C4 experimental campaign. The WMS uses the wall surface temperatures from 6
fields of view of the Infrared viewing system. It extracts the raw digital data
from selected areas, converts it to temperatures using the calibration and
write it on the shared memory network being used by the Plasma Control System
(PCS). The PCS feeds back to actuators, namely the injected power from 5
antennae's of the lower hybrid and ion cyclotron resonance radiofrequency (RF)
heating systems. WMS activates feed back control 63 times during C4, which is
14% of the plasma discharges. It activates mainly as the result of a direct RF
loss to the upper divertor pipes. The feedback control maintains the wall
temperature within the operation envelope during 97% of the occurrences, while
enabling plasma discharge continuation. The false positive rate establishes at
0.2%. WMS significantly facilitated the operation path to high power operation
during C4, by managing the technical risks to critical wall components.
