MXPA06005467A - Test access matrix (tam) protector module and associated circuitry for a telecommunications system - Google Patents

Abstract

A Test Access Matrix (TAM) system permits installation onto an existing connector block. The TAM system exhibits a configuration that permits installation on to telecommunications circuits at the connection point provided for installation of protection modules or other devices that are inserted into the telecommunications circuit. The installation can be accomplished either before new or after existing connector blocks are installed on a telecommunication cross connect frame, tie frame, or other support structure. The TAM system can be instructed to connect a two or four wire test bus to any of the individual telecommunications circuits that are connected to the connector block. The test bus can be connected to the individual communication circuits in either a bridging, break towards the distribution side of the local loop, break towards the telecommunications equipment, or an insertion into the line via a"make before break"sequence. The bus can be further redirected to multiple test or monitoring devices.

Description

PROTECTIVE MODULE OF TEST ACCESS MATRIX (TAM) AND ASSOCIATED CIRCUITERIA FOR A TELECOMMUNICATION SYSTEM FIELD OF THE INVENTION The nature of the Regular Old Telephone Systems (POTS) equipment in the telecommunications industry is such that a test facility can locate faults in the local loop through the Central Office (CO) team. Test facilities for locating faults in the local loop that affect high-speed data systems such as DSL typically need to be located between the OC equipment and the local loop. The test facility is changed to the line that needs to be tested using what is known as the Test Access Matrix (TAM). The TAM typically switches one of a plurality of two-wire telecommunications circuits to a two- or four-wire test link. The connector blocks are typically installed in the Main Distribution Frames (MDF) in the CO, between the OC equipment and the local loop. Some connector blocks include contacts for mounting the protective modules, which are electrically connected to the contacts, a TAM module, according to the present invention, which can be plugged into the contacts in existing blocks in the MDF, offers a substantial benefit over a conventional TAM that replaces an existing block. The installation cost and the system downtime due to the installation of a plug in TAM are reduced when compared to a unit that must be installed through the existing infrastructure or removing existing hardware that was permanently installed and installing new hardware Permanently. Other plugs have been proposed in these devices but, to date, a device that is sufficiently robust and compact to be considered adequately reliable has not been seen. The present invention provides a means to provide the functionality and reliability required for an acceptable installation cost. This solution offers the additional advantage of having simple twisted pair counting TAM modules. In the rare case that a module fails, the adjacent circuits are not affected. It is also possible to use multiple low twisted pair counting tanks (which integrate several TAM modules for simple torque counting) supporting a small installation saving but negatively impacting the cost of the cycle duration.

SUMMARY OF THE INVENTION The present invention is a TAM system that is installed in a single terminal, five terminals or another type of connector block / telephone protector. The TAM system includes a plurality of TAM modules, a mother board with an integral control matrix preferably and a controller which are installed in a connector block. The TAM modules have relays and integrated overvoltage protection devices. Additional connections are required for connection in interface with the motherboard instead of the 5 standard connections used in typical simple circuit protective modules. The motherboard is installed between the protective modules and the connection field of the block. A controller can be integrated into the motherboard, installed on the block, or remotely located. The control function is designed to facilitate the connection of multiple blocks to each other for control purposes using a low cable counting link. This and other objects, features and advantages of the present invention will become apparent from the following detailed description of the illustrative embodiments thereof, which will be read in connection with the appended figures.

BRIEF DESCRIPTION OF THE FIGURES Figure 1 is a block diagram of the overall Test Access Matrix (TAM) system of the present invention. Figure 2 is a detailed schematic diagram of the preferred circuit of a TAM module of the present invention, forming part of the system shown in Figure 1. Figure 3A is a detailed schematic diagram of a portion of the circuit of the TAM module shown in Figure 2 in a first test mode. Figure 3B is a detailed schematic diagram of a circuit portion of the TAM module shown in Figure 2 in a second test mode. Figure 3C is a detailed schematic diagram of a portion of the circuit of the TAM module shown in Figure 2 in a third test mode. Figure 3D is a detailed schematic diagram of a portion of the circuit of the TAM module shown in Figure 2 in a fourth test mode. Figure 4 is a schematic diagram of the control matrix of the motherboard of the present invention, forming part of the TAM system shown in Figure 1.

Figure 5 is an isometric view in parts of the components of the selected TAM system of the present invention mounted on a standard single-ended connector block. Figure 6 is an isometric view in parts of the components of the selected TAM system of the present invention mounted on a standard five-terminal connector block. Figure 7A is a detailed schematic diagram of a portion of the TAM module circuit having two relays for interfacing with a two-wire test link and shown in a normal mode of operation (that is, it is not shown in test mode). Figure 7B is a detailed schematic diagram of the two-relay TAM module shown in Figure 7A in a first test mode. Figure 7C is a detailed schematic diagram of the two-relay TAM module shown in Figure 7A in a second test mode. Figure 7D is a detailed schematic diagram of the two-relay TAM module shown in Figure 7A in a third test mode.

DETAILED DESCRIPTION OF THE INVENTION In accordance with one form of the present invention, a Test Access Matrix (TAM) system includes a plurality of protected TAM modules 1 (1) to (n). The modules 1 are connected to a motherboard (for example, a printed circuit board) (2) which, as illustrated in FIGS. 5 and 6, can be mounted on one side of a connector block, as shown in FIG. will describe in more detail. The TAM system of the present invention also includes a control matrix (3) and a controller (4), for example, a circuit, which receives a control signal from the Central Office (CO) to initiate, for example, a test of the OC equipment or the local loop (also referred to in the present invention as the distribution). The controller (4) and the control matrix (3) can be placed on the motherboard (2) of the TAM system, or they can be placed far away from the motherboard (2). As shown in figure 1, the controller (4) receives CO control signals, as mentioned above, said control signals contain information designating the telephone circuit that should be tested and the type of test to be executed. The controller (4) can be a demultiplexer circuit or a programmable read-only memory (PROM), or a random access memory (RAM), or even more preferably, a microcontroller or a dual-tone multifrequency controller (DTMF) which, preferably, has 1/0 (input / output) TTL outputs (Transistor to Transistor Logic), as shown in Figure 4, or any other type of controller circuit known to those skilled in the art. The controller (4) provides signals in a single cable or a link to the control matrix (3) which, in turn, provides signals to the selected TAM modules (1) to test a particular telephone circuit, either in the distribution side or team side, or both, and to select the particular test to be performed. As can be seen in Figure 1, each protected TAM module (1) is connected to a particular telephone circuit and passes through it to and from the local loop (ie, the distribution side) and signals to and from it. the CO (that is, the equipment side). When a particular telephone circuit is selected for testing, the control matrix (3) activates the relays or other switching circuits in the corresponding TAM module (1) a (n) associated with that telephone circuit. Each module TAM (1) to (n) is connected to a test link, and the particular TAM module, which has relays or switching circuits that are activated by the control matrix (3), provides the test link with test signals that represent, and from which it can be determined, the condition of the telephone lines associated with it, that is, the lines of the CO or the local loop, or both. The test link is provided to the CO, which can then determine, from the signals carried on the test link, if there is a problem with the lines, the type of problem (for example, a short circuit or open circuit) , and the side (that is, the side of the equipment, or the distribution side) in which the problem occurs. The preferred circuit of the TAM module (1) is shown in Figure 2. The TAM module preferably includes three relays (5) - (7) and a protective circuit (8). Although the relays (5) - (7) are shown, it is contemplated within the scope of the present invention to replace solid state circuits that perform the same function as the relays with the relays. The relays (5) - (7) are shown in figure 2 as single-shot and double-pole relays. It is also possible to use double throw and double pole relays, double throw and single pole relays, and single shot and single pole relays. The protective circuit (8) shown in Figure 2 is a partially balanced solid-state surge suppressor, as is known in the art, and includes three thyristors, two of which are connected in series between the two outputs of module distribution, referred to in figure 2 by means of the AD and BD annotation, which are often referred to as the lines a and b, ("Tip" and "Ring"), and the other thyristor is connected between the serial connection of the first two thyristors and the ground connection. Of course, any overcurrent / overvoltage protective circuit (8) or components known in the art may be employed, as required by the user. Referring again to Figure 2, two separate contacts of each of the first two relays (5) and (6) are connected to the wires of a four-wire test link, which is connected to other TAM modules and which it is routed to the CO so that the signals provided by the activated relays can be evaluated by the CO. The first relay (5) has one end of its coil connected to a control line, referred to in Figure 2 as the ControlE works / and similarly, the second relay (6) has one end of its coil connected to a ControlD try The other ends of the coils of the first and second relays (5) and (6) are provided to an energy link. The third relay (7) of the preferred TAM module (1) has one end of its coil connected to another line referred to in Figure 2 as an InterBarrage / and the other end of its coil is connected to the aforementioned energy link. Accordingly, the energization of one or more ControlE lines / Controls Control Control and the power link will activate one or more of the three relays (5) - (7). The computer circuit telephone lines are provided to the TAM module (1) and are shown in figure 2 by means of the annotation AE and BE. The two lines of equipment are connected to two contacts of the third relay (7) and the other two contacts of the first relay (5). The other corresponding contacts of the third relay (7) are connected to the other contacts of the second relay (6) and to the protection circuit (8) and the output terminals or plugs can be connected to the distribution lines, named in the figure 2 as AD and BD. The TAM module (1) is shown in Figure 2 in its normal, non-test state. The third relay (7) is energized so that the equipment signals on the lines AE and BE pass through the contacts of the relay respectively to the distribution lines AD and BD, which are protected by the protective circuit (8). The first relay (5) and the second relay (6) are not activated and, therefore, neither the equipment lines AE and BE nor the distribution lines AD and BD are connected to the four-wire test link. Figures 3A to 3D show the activated states of the relays in the TAM protective module (1) in four different test modes. The activated states of the relays (5) - (7) can be configured to run tests as required, including the inactive mode or monitor, as shown in Figure 3A; the deviation mode towards the equipment, as shown in Figure 3B; the deviation mode towards the distribution, as shown in Figure 3C; and the way to execute before dividing deviation, as shown in Figure 3D. Very specifically, in the inactive mode or monitor (Figure 7A), the relays (5) and (7) are activated to close their contacts while the relay (6) is not activated and their contacts remain open so that the lines of the equipment connect to the local loop or distribution while the lines are being monitored on two wires of the test link preferably four wires. In the deviation mode to the equipment (figure 7B), the relay (7) is deactivated to open its contacts, so that the signal coming from the equipment does not pass through the TAM module to the distribution lines, and the first relay (5) it is activated to close its contacts so that the lines of the equipment are connected to the two cables of the test link, preferably four cables in order to monitor the signal from the Central Office (CO). The relay (6) is deactivated and your contacts remain open. In the diversion mode towards distribution (figure 7C), again the third relay (7) is deactivated so that its contacts open, thus cutting the connection between the equipment lines and the distribution lines, and the second relay (6) is activated to close its contacts. so that two cables of the test link preferably four cables are connected to the local loop (distribution lines). In this mode, the first relay (5) is deactivated so that its contacts are open. In the run before split deviation mode (figure 3D), the third relay (7) is deactivated so that its contacts are opened, thus cutting the connection between the equipment and the local loop, and the first relay (5) and the second relay (6) are activated to close their respective contacts, so that two wires of the four-wire test link are connected to the lines of the equipment, and the other two wires of the four-wire test link are connected to the lines of distribution. Figure 4 shows the control matrix (3), which is preferably placed on the motherboard (2). The control matrix (3) is preferably a circuit employing drive switches, such as transistors, which activate the relays (5) - (7) in the TAM modules (1) to (n). Any number of TTLs or microprocessor-based control circuits, known in the art, can be used to execute the control function of the control matrix (3). Due to the need to direct only one circuit that passes through a TAM module (1) to the test link at the same time, the control matrix (3) can be used to minimize the connections of the controller (4) to the motherboard (2). The control matrix (3) shown in Figure 4 is for a 100-wire pair TAM system. Each of the 300 relays shown (Kl to KIOOc) is in the TAM modules. For example, the relays Kla, Klb, and Klc are in the TAM module number 1. The Kna relay is shown by means of the reference number (5) in figure 2, the Knb relay is shown by means of the reference number ( 6) in figure 2, and the Knc relay is designated by the reference number (7) in figure 2. The protection diodes Day, Dlb, Dlc to DIOOc are connected in parallel with the relay coils of the Kla relays , Klb, Klc to KIOOc with a normally non-conductive polarity to avoid damage to the control matrix (3) due to the high voltage spikes caused when the relay coils are turned off, as is known in the art.

The control circuit (13) of the controller (4) sends signals to the control matrix switches (3) . In the case of the control matrix (3) shown in Figure 4, the switches are transistors Ql to Q35. The control circuit (13) that generates the 1/0 signals that control the states of the switches (transistors) Ql to Q35 is located in the controller (4). Switches / transistors Ql to Q35 can be located on the motherboard (2) or controller (4). For the 100-wire TAM system, one to three switches (transistors) can be activated in each row R of the control matrix (3) (from the transistor Ql (14) to the transistor Q15 (15) comprise the first row) for provide the voltage of the relay coil (16), also referred to as Vcc, to a column of modules. Similarly, a switch may be activated in column C of the switches (from transistor Q16 (18) to transistor Q35 (19) comprise a column) to provide the ground return of the signal circuit (17) to a row of modules. Relays (5) - (7) will be activated in the TAM module (1) at the intersection of row R and column C. The combination and sequence of activated relays will cause the activated TAM module (l) - (n) allow the test link to test the chosen circuit in one of the four test configurations shown in Figures 3A-3D.

Figure 5 illustrates the TAM system of the present invention installed in a standard single terminal connector block (which has a plug for receiving the ground terminal of the protective module, and four straight terminals for the equipment lines and the distribution lines , which are received by the plugs in the respective protector or TAM module). The connector block (20) shown has the motherboard (21) on the side of the connection field of the connector block (20) over the terminals (22) in the block for the equipment line connections and distribution. The motherboard (21) preferably does not make electrical contact with the terminals (22) in the block. Therefore, the motherboard (21) may have through holes formed through the thickness thereof, which are aligned with the terminals and receive said terminals (22) of the connector block (20), the through holes are isolated from the rest of the circuit on the motherboard (21). The connections of the equipment and distribution inside the module (23) form a direct electrical connection with the terminals (22) in the connector block (20). The control connections and the test link of the TAM module (23) are made through a connector (30) mounted on the module that connects with a respective connector (25) of a plurality of connectors located on the motherboard ( twenty-one) . The ground terminal of the module (24) for the protective circuit (8) with the TAM module (23) makes an electrical connection with the connecting block to ground. Figure 5 shows three TAM modules (23), two of which have their housings removed to show the interior of the module. One of the modules (23a) is shown with the first relay (5), the second relay (6) and the third relay (7). The other module (23b) with the housing removed shows a mode in which only the first relay (5) or the second relay (6), and the third relay (7) are used. You can omit one of the first and second relays (5) and (6), in case you want fewer test modes. It should be appreciated that with only two relays, additional space can be supported in the TAM module for the circuitry, or the module can be made smaller. In addition it should be appreciated that the relays (5) - (7) can be rotated on their side inside the module to support additional space, or the three relays (5) - (7) can be accommodated in a single plane on a board printed circuits inside the module. Figure 6 illustrates the TAM system of the present invention installed in a standard five terminal block connector (26). The connector block (26), shown in Figure 6, has the motherboard (27) installed on the side of the connection on the block (26). The distribution and equipment connections in the connector block (26) are the plugs (28). Preferably, the motherboard (27) does not make electrical contact with the plugs in the block (28) or the distribution terminals and equipment and the earth terminals (29) that extend from the TAM module. As in the previous embodiment shown in Figure 5, the motherboard (27) can include through holes (35) formed through the thickness thereof, said holes (35) receive the distribution terminals and equipment (29) and the ground terminal (31) of the module. The distribution and equipment connection terminals (29) protruding from the module (23) make a direct electrical connection with the plugs (28) in the connector block (26) through the through holes (35) of the motherboard (27). The TAM modules (23), both in the embodiment shown in Figure 5 and in the embodiment shown in Figure 6, include a connector (30) for the connections of the test and control link of the module. This connector (30) is coupled with a cooperating connector (25), of a plurality of cooperation connectors placed on the motherboard (27) and located in alignment with the connectors (30) of the TAM modules (23). Therefore, the connections of the test and control link of the module make a direct connection to the motherboard (27). The ground terminal of the module (31) for the protective circuit makes an electrical connection with the grounding plug of the connector block (32) through a respective through hole (35) of the motherboard (27).

Figures 7A to 7D illustrate a circuit of the TAM module designed in accordance with the present invention to be interfaced with a two-wire test link. Only two relays (40) and (41) are required. The designations "nc" and "no", in figures 7A to 7D respectively, refer to the "normally closed" and "normally open" position of the relay contacts (40) and (41) for the module circuit TAM that connects in interface with a two-wire test link. Each respective equipment line is connected to a respective normally open contact of the relay (40). The two distribution lines are connected to the respective switching contacts of the relay (41). The normally closed and normally open contacts of each relay switching circuit (40) are connected to the normally open and normally closed contacts, respectively, of each corresponding switching circuit of the relay (41). The two-wire test link lines are connected to the switching contacts of the relay (40). Very specifically, Figure 7A shows the normal mode of operation for the TAM module circuit for the two-wire test link mode. Each line of equipment is directly connected to a respective distribution line, and the test link lines are not connected either to the equipment lines or to the distribution lines. Each switching circuit of each of the relays (40) and (41) is in its normally closed state so that the lines of the equipment are electrically connected through the relay (41) to the distribution lines. Figure 7B shows the circuit of the TAM module for the two-wire test link in the "inactive" mode. In this mode, each relay switching circuit (40) is in a normally open state, and each relay switching circuit (41) is in a normally closed state. The lines of the equipment are electrically connected to the distribution lines through the relay (41), and the lines of the test link are connected through the relay (40) to the lines of the equipment. Figure 7C shows the circuit of the TAM module for a two-wire test link in the equipment test mode. Here, the connection between the equipment lines and the distribution lines is interrupted by the relay (41). The equipment lines are connected through the relay (40) to the test link lines. The switching circuits of the relay (40) are in their normally open state, and the switching circuits of the relay (41) are in their normally open state.

Figure 7D illustrates the circuit of the TAM module for the two-wire test link in a distribution test mode. The connection between the equipment lines and the distribution lines is interrupted through the respective switching circuits of the relay (41), but each test link line is connected to a respective distribution line through the switching circuits of the relays (40) and (41). The switching circuits of the relay (40) are in their normally closed state, and the switching circuits of the relay (41) are in their normally open state. As can be seen from Figures 5 and 6, the TAM system of the present invention adds only the thickness of the motherboard (21) and (27) and its components to the existing space allocated for the connector block, and can be Couple with a conventional connector block. The conventional protection modules are removed from the connector block, and the motherboard (21) and (27) is fitted thereto, as shown in figures 5 and 6. The TAM protective modules (23) of the present invention replace the conventional protective modules and are coupled with the terminals or plugs of the connector block in the same way as the conventional protective modules coupled with the connector block. Therefore, you do not have to install a TAM circuit that replaces an existing connector block by cutting the existing infrastructure or removing the existing permanently installed hardware. Even in the rare case that a TAM module fails, the adjacent circuits are not affected. Furthermore, although individual modules are shown in FIGS. 5 and 6, it is contemplated that it is within the scope of the present invention to have tanks comprising a plurality of modules that are coupled to the connections of the equipment or distribution of the connector block, partially or in its entirety, through a row or column of connections in the connector block. In addition, in the case where protection is not required, a TAM module with relays (5) - (7) and without protection circuit (8) can be used to reduce costs. Additionally, protective modules can be used that have a single protection circuit (8), without relays (5) - (7), when a test link of two cables or four cables is not required. Although exemplary embodiments of the present invention have been described herein with reference to the appended figures, it will be understood that the invention is not limited to those precise embodiments, and that those skilled in the art can make other changes and modifications thereto without departing from the spirit of the invention. scope or spirit of the invention.

Claims (12)

NOVELTY OF THE INVENTION Having described the present invention, it is considered as a novelty and, therefore, the content of the following is claimed as a priority: CLAIMS

1. - A Test Access Matrix (TAM) system that operates with a connector block of a telecommunications system for testing telecommunications lines connected to the connector block, which comprises: a mother board that can be mounted on the connector block, motherboard has at least a first connector mounted thereon and a test link electrically connected to at least one first connector; at least one TAM module having an electrical circuit, at least the TAM module has a second connector mounted thereon which is electrically connected to at least one first connector mounted on the motherboard and the test link; a control matrix, the control matrix is electrically connected to at least one first connector of the motherboard and, through it can be electrically connected to at least one TAM module, the control matrix provides an output signal at least one TAM module for selectively placing the electrical circuit of at least one TAM module in a normal operating mode and at least one test mode; and a controller, the controller responds to an input control signal and generates an output signal from the controller provided to the control matrix, the control matrix provides the matrix output signal to at least one TAM module in response to the output signal of the controller thus received. 2.- The Test Access Matrix system (TAM) according to claim 1, characterized in that the electrical circuit of at least one TAM module includes at least one switching element, at least the switching element can be changed between a first state corresponding to the normal operating mode at least one TAM module and a second state corresponding to at least one test mode of at least one TAM module in response to the output signal of the array. 3. The Test Access Matrix (TAM) system according to claim 2, characterized in that at least the switching element is a relay. 4. The Test Access Matrix (TAM) system according to claim 2, characterized in that at least one TAM module also includes a protective circuit electrically coupled to the electrical circuit thereof. 5. The Test Access Matrix (TAM) system according to claim 1, characterized in that the connector block includes at least one side having a plurality of straight terminal contacts extending therefrom; wherein the motherboard is in the form of a printed circuit board having a plurality of through holes formed through the thickness thereof, the mother board can be mounted on the connector block on at least one side thereof, the plurality of straight terminal contacts is received by the plurality of through holes and extends through the motherboard; and wherein at least one TAM module can be electrically coupled with a portion of at least one straight terminal contact of the plurality of terminal contacts extending through the motherboard. 6. The Test Access Matrix (TAM) system according to claim 1, characterized in that the connector block includes at least one side that has a plurality of plugs formed therein; wherein the motherboard is in the form of a printed circuit board having a plurality of through holes formed through the thickness thereof, the mother board can be mounted on the connector block with the respective through holes of the plurality of pass holes aligned with the corresponding plugs of the plurality of plugs of the connector block; and wherein at least one TAM module includes at least one terminal contact, at least that terminal contact can be received through a through hole of the plurality of through holes of the motherboard and that extend through it and that can be received by a plug of the plurality of sockets of the motherboard. connector block. 7.- A Test Access Matrix (TAM) protective module that can be mounted on a connector block of a telecommunications system to protect and test telecommunications lines connected to the connector block, the TAM protective module is in electrical communication at less with a pair of lines of telecommunications equipment and a pair of telecommunication distribution lines and a test link, the TAM protective module comprises: a test circuit selectively in electrical communication with at least one of the pair of equipment lines of telecommunications and the pair of telecommunications distribution lines; and a protective circuit, the protective circuit is in electrical communication with at least the pair of telecommunication distribution lines. 8.- The Test Access Matrix (TAM) protective module according to claim 7, characterized in that the test circuit of the TAM module includes at least one switching element, at least that switching element can change between a first state, wherein at least one of the pair of telecommunication equipment lines and the pair of telecommunication distribution lines is in electrical communication with the test link, and a second state wherein the pair of telecommunication equipment lines Telecommunications and the pair of telecommunications distribution lines are not in electrical communication with the test link. 9.- The Test Access Matrix (TAM) protective module according to claim 8, characterized in that at least the switching element is a relay. 10.- The Test Access Matrix (TAM) protective module according to claim 7, characterized in that the test circuit is a switching circuit, the switching circuit can change between a first state, wherein the pair of lines of telecommunications equipment is in electrical communication with the test link, a second state, where the pair of telecommunication distribution lines is in electrical communication with the test link, a third state, where each pair of lines of telecommunications equipment and the pair of telecommunications distribution lines is in electrical communication with the test link, and a fourth state, where the pair of telecommunication equipment lines and the pair of telecommunications distribution lines are not in electrical communication with the test link. 11. The Test Access Matrix (TAM) system according to claim 1, characterized in that the control matrix includes a plurality of switching elements, each switching element of the plurality of switching elements can change between a first conductive state and a second non-conductive state, the first conductive state and the second non-conductive state of the selected switching elements of the control matrix determine the output signal of the matrix provided to at least one TAM module. 12.- A Test Access Matrix (TAM) system that operates with a connector block of a telecommunications system to test telecommunications lines connected to the connector block, which comprises: a motherboard that can be mounted on the connector block , the motherboard has a plurality of first connectors mounted therein and a test link electrically connected to the plurality of first connectors; a plurality of TAM modules, each TAM module has an electrical test circuit and a protective circuit, each TAM module of the plurality of TAM modules has a second connector mounted thereon which can be electrically connected to a respective first connector of the plurality of first connectors mounted on the motherboard and, therefore, can be connected to the test link; a control matrix, the control matrix is electrically connected to the plurality of first connectors of the motherboard and, through them can be electrically connected to at least the plurality of TAM modules, the control matrix provides a signal of matrix output to the plurality of TAM modules for selectively placing the electrical test circuit of the plurality of TAM modules in a normal operating mode and at least one test mode; and a controller, the controller responds to an input control signal and generates an output signal from the controller provided to the control matrix, the control matrix provides the matrix output signal to a respective TAM module of the plurality of modules TAM in response to the output signal of the controller thus received.