Front hadron calorimeter of the European hybrid spectrometer monitoring system

A complex system for light control (SLC) of the front hadron calorimeter (FHC) of the European hybrid spectrometer is described. The FHC includes 200 plastic scintillators. The SLC permits to conduct autonomous correction of multiplication factor drift of photoelectron multipliers (PEM) and to identify failed elements. Control functions are exercised by two independent subsystems. The first one is a part of the general system of data acquisition. The second one - a system of on-line control of FHC state is intended for continuous successive by-channel analog-to-digital transformation of signals-responses on reper light pulses recorded from the PEM dinodes. The systems are presented in the CAMAC standard. The structural diagram of the system, functional correlation of modules and ideology of software are presented. On-line control permits to bring the detector in the mode corresponding to any of earlier conducted calibrations at the accuracy of 5%