A triangular waveform generator includes a square waveform clock circuit and an integrating circuit. The organic electroluminescent display device may include first power supply line for supplying power supply voltage to pixels, and second power supply line for supplying voltage to an electrode on the upper side of the pixel. By storing these tables in the transmitter, the problem that the receiver has to wait for them to occur in the multiplex signal is overcome. Because the procedure produces spectral information independently of the number of data frames acquired during the interferometric scan, it is materially more rapid than conventional FFT analysis. A collection module organizes the activity indicators into trace data representative of the resource activity. A signal containing information about the image is transmitted to a remote central station.