LABORATORY PROCEDURE I Sampling A. The time division Multiplexer (TDM MUX) module is used to recombine two analog signals into one data stream. The input A is connected to the OUT connector for a period T (T = 1/fs). During the next period, input B is connected to the OUT connector. The process then repeats. It should be obvious that each input, input A(or B) is “Sampled” at a rate equal to ½ fs as set by the Master clock. NOTE: The actual waveform sampling rate = ½ fs as set by the “DATA/Sampling RATE”, output, mentioned above (. to. | EXPERIMENT 7 DATA ACQUISITION 1 27 2010 Group DATA ACQUISITION PURPOSE The objectives of this laboratory are 1. To examine signal sampling aliasing and signal reconstruction. 2. To implement a time division multiplexing system. 3. To investigate the quantization error associated with analog-to-digital conversion. EQUIPMENT LIST 1. PC with Matlab and Simulink. LABORATORY PROCEDURE I Sampling A. The time division Multiplexer TDM MUX module is used to recombine two analog signals into one data stream. The input A is connected to the OUT connector for a period T T 1 fs . During the next period input B is connected to the OUT connector. The process then repeats. It should be obvious that each input input A or B is Sampled at a rate equal to 4 fs as set by the Master clock. NOTE The actual waveform sampling rate 4 fs as set by the DATA Sampling RATE output mentioned above . to sample a 1kHz cosine using this equipment at the Nyquist rate then fs would have to be set to 4 kHz B. Next the fs were set to 10kHz and the function generator frequency was set to 1kHz. The output signal OUT was observed on a scope and was also compared with the input on a dual channel scope. The value of fs was slightly adjusted for a stable display. The scope was moved to the sample-and-hold S H output. We see that the amplitude variations during the sampled period are now replaced with a constant flat top . Figure 7a - Sampling using Sample and .