1.- To study the main actions and signals involved in a digital commutation.
2.- To study the dynamic channel assignment and temporal switching.
3.- To study the standards for audio conversion.
4.- To establish of a communication between some channels step by step.
5.- Visual monitoring of the main states that a line goes through during a call.

6.- To configure lines as only receiver, transmitter,receiver / transmitter.
7.- To test of the conversion from 2 to 4 wires.
8.- To study the electric stages when the user makes actions over the telephone.
9.- To study the signals involved when dialing by pulses.
10.- To study the signals involved when dialing by tones.
11.- To study the tone signal.

1. CODITEL. Trainer:

System is mounted on a desktop box. Diagram in the front panel of the unit with the same structure as the real hardware. Provides access to all main signals. Follows all the recommendations of CCITT (Cosultive Comitte International Telephony and Telegraphy). Structure is based on the standard for digital commutation systems. Time division multiplexing(TDM)and Pulse code Modulation (PCM) principles. Communication based on a temporal commutator that supports up to fifteen complete internal communications with two MIC ways, one inlet way and one outlet way. Standard MIC system of 32 channels with dynamic assignament and frame synchronization. 30 channels used for voice transmission and 2 used for signalling and synchronism. Internal hardware consists of two electronics boards: an analog board with all integrated and discrete analog elements and a digital board. Structure integrated with all the internal
common elements in a telephone system: subscriber´s line, tone generator, base of times, filtering stage, switching matrix, number decoders and control memory. Functions as battery feed, overvoltage protection, ringing, coding and decoding, supervision, signalling, 2-4 wires conversion and test( BORSCHT functions) covered, in each line. High precision digital tone synthetizer 400 Hz using Direct Digital Synthetizer(DDS). Four commercial receptors (telephones), two used for signaling by pulses and other two for tones. Switching memory matrix, control memory and base of times implemented with FPGA technology with high stability and fiability. Standard protocol for communication between the PC and the trainer. CODITEL is a digital circuit commutation unit for didactic purposes. Its structure is like a temporal commutator structure with two MIC ways, one inlet way and one outlet way. Basically, it follows the recommendation of the CCITT and of Telephony.

2. CODITEL/CCSOF. Computer Control and Graphic Visualization Software:

Compatible with actual Windows operating systems. Compatible with the industry standards. In combination with the hardware, Coditel Software is supplied with the system. Coditel software has a user friendly graphical interface that provides totally control and visualization of the telephone system.