Block diagram

Cricuits of the exchange are located on cards of a printed circuit,that can be plugged to the metal case, by the following division:

There are several circuits on a peripheral card (4..16) with the same build-up. These cards are connected to each other with a printed backboard wiring. Computer is located on the left side of the case, and circuits of the peripheral unit are on the right side. The switching field - PCM bus - is realized in the backboard wiring.

We can identify circuits - and devices connected to them - in the database of the exchange on the basis of a physical address (port address)::

szekrény module card circuit
example: 0 1a 03 01

Example is the port address of a digital telephone. Since the exchange consists of one module, the first three characters of the port address (01a) is the same in the case of every port.

Block diagram of the exchange is demonstrated on the following figure: