DE10113305A1 - Transmission medium testing method uses testing of hierarchy stages for accurate isolation of fault module - Google Patents

Abstract

The testing method has the modules (2a,2b,2c,2d; 3a,3b,3c,3d) using the transmission medium (12b) divided into 2 groups assigned to first and second fall out units (D,E), both assigned to a common fall out unit (B), with initial testing of the latter, followed by testing of the first and second fall out units when a fault is detected. An Independent claim for a test control for testing a transmission medium used simultaneously by several modules is also included.

Description

The invention relates to a method for testing one of meh rere modules of shared transmission medium. except the invention relates to a control device for use implementation of such a test.

In electrical or electronic systems, for example in telephone exchanges, local computer networks, etc., multiple system modules communicate, e.g. B. several e electronic assemblies, computers, etc. via a common ge used transmission medium such as a bus system.

Bus systems usually consist of one or more Line systems, e.g. B. from a data bus for the transmission of Data, an address bus for transferring memory addresses, and / or a control bus that has one or more (central) Has control lines.

For example, in a digital subscriber or Connection line group of a digital telephone Switching system a variety of different electronic Modules connected to a PCM bus system ("PCM" = Pulse Code Modulation).

Due to the shared use of the bus system by several Due to a defective module, the functionality of the entire bus system.

The invention therefore has for its object a method for ver to provide with which one of several modules shared transmission medium, e.g. B. a bus system, ge can be tested. The invention further aims to to provide a control unit, which during the implementation  of a test method according to the invention can be used can.

The invention achieves this and other goals through Ge subjects of claims 1 and 9. Advantageous further developments the invention are specified in the subclaims.

According to a basic concept of the invention, a transmission medium shared by several modules first a first group of modules for a first out folding unit, a second group of modules to a second Failure unit, and the modules of the first and second mo dulgruppe to one of the first and the second failure unit assigned to higher-level failure unit. Then the higher-level failure unit tested. Only if mitit It is stated that the higher-level failure unit is faulty the first and second failure units are tested.

So it will initially be a failure unit of a higher, and then failure units of a lower hierarchy level testing. This allows the position of a module, which the radio functionality of the entire bus system disturbs with increasing Ge accuracy can be determined.

In the following, the invention is illustrated by means of an embodiment game and the accompanying drawing explained. In the Drawing shows:

Fig. 1 is a schematic representation of a portion of a line group of a digital telephone switching system;

Fig. 2 is a flow chart showing method steps performed in the invention.

Fig. 1 shows a schematic representation of a section 1 of a line group of a digital telephone switching system, in the housing of which a plurality of electronic modules 2 a, 2 b, 2 c, 2 d, 3 a, 3 b, 3 c, 3 d is arranged , Four modules 2 a, 2 b, 2 c, 2 d and 3 a, 3 b, 3 c, 3 d are combined to form a module section 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , Each section 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 has an interface unit 4 a, 5 a, 6 a, 7 a, 8 a, 9 a, 10 a, 11 a, via which to a Section 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 belonging modules 2 a, 2 b, 2 c, 2 d, 3 a, 3 b, 3 c, 3 d to a system control bus system 12 a, and on a PCM bus system 12 b can be connected ("PCM" = pulse code modulation). The modules 2 a, 2 b, 2 c, 2 d, 3 a, 3 b, 3 c, 3 d can thus - with the interposition of the corresponding interface units 4 a, 5 a, 6 a, 7 a, 8 a, 9 a , 10 a, 11 a - communicate with each other by applying data and control signals corresponding to the PCM bus protocol via the PCM bus system 12 b.

Furthermore, the switching center connection group has a central test control device 13 which is connected to the system control bus system 12 a. Via the system control bus system 12 a, the test control device 13 and the modules 2 a, 2 b, 2 c, 2 d, 3 a, 3 b, 3 c, 3 d - with interposition of the corresponding interface units 4 a, 5 a , 6 a, 7 a, 8 a, 9 a, 10 a, 11 a - communicate with each other.

On the PCM bus 12 b can use different types occur in principle two errors: first, (for example the module section. 4) can be prepared by a defek te module section the functionali ty of the PCM bus system 12 as a whole be disrupted b (Error group X). This is e.g. B. the case when one or more lines of the PCM bus system 12 b are continuously pulled to ground by a certain, defective module section (here: the module section 4 ). Also, the modules in non-defective module sections 5, 6, 7, 8, 9, 10, 11 may then via the bus 12 b no longer communicate with each other.

Furthermore, a module section (e.g. module section 8 ) can be faulty in such a way that the non-defective sections can no longer communicate with the faulty section 8 , but an error-free data exchange between the not defective sections is possible (error group Y). This can e.g. B. be the case when the section 8, after it has been addressed by a non-faulty section, response signals to the bus 12 b at places which do not correspond to the bus protocol, after which the non-defective section terminates the communication according to the protocol.

To carry out bus system tests, the modules 2 a, 2 b, 2 c, 2 d, 3 a, 3 b, 3 c, 3 d connected to the bus system 12 b are different failure units A, B, C, D, E, 4, 5, 6, 7, 8, 9, 10, 11 assigned. The failure units A, B, C, D, E, 4, 5, 6, 7, 8, 9, 10, 11 are hierarchically structured: The failure units on the lowest level correspond to the above-mentioned module sections 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 . For example, as mentioned above, modules 2 a, 2 b, 2 c, 2 d are assigned to module section 4 (first failure unit at the lowest level), and modules 3 a, 3 b, 3 c, 3 d of module Section 5 (second failure unit at the lowest level), etc.

The failure unit D (first failure unit, second lowest level) are all modules 2 a, 2 b, 2 c, 2 d, 3 a, 3 b, 3 c, 3 d of the module sections 4 , 5 , ie the first and second off assigned to the lowest level, and the failure unit E (second failure unit, second lowest level) contains the modules contained in the module sections 6 , 7 .

Furthermore, the failure unit B (first failure unit middle level) comprises all modules 2 a, 2 b, 2 c, 2 d, 3 a, 3 b, 3 c, 3 d of the failure units D, E assigned to it (first and second failure units second lowest level), and the failing unit C (second failing unit middle level) all modules of the module sections 8 , 9 , 10 , 11 assigned to it .

Corresponding to the failure unit A (failure unit highest ter level) all modules of the failure units B, C (first and second middle level failure unit).

According to FIG. 2, the failure unit to be tested is first selected in a first test step (I) (here: the failure unit A (failure unit at the highest level)). Then, it is ensured in a test step (II) that all Mo dul-sections 4, 5, 6, 7, 8, 9, 10, 11 of the test in each case the failure of unit A (failure unit highest level) to the PCM bus 12 b are connected. This can e.g. B. happen that the module sections 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 are manually connected to the bus system 12 b. Alternatively, e.g. B. cause the central test control device 13 by applying appropriate signals to the system control bus system 12 a that the module sections 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 are connected to the PCM bus system 12 b.

Next, in a third step (III), those modules 2 a, 2 b, 2 c, 2 d, 3 a, 3 b, 3 c, 3 d are selected that simultaneously test the PCM bus system 12 b in a parallel manner sol len (here: all modules 2 a, 2 b, 2 c, 2 d, 3 a, 3 b, 3 c, 3 d) belonging to the failure unit A (failure unit at the highest level). The selection is made e.g. B. by the central test control device 13 , which then communicates by applying corresponding signals to the system control bus system 12 a to the respectively selected modules 2 a, 2 b, 2 c, 2 d, 3 a, 3 b, 3 c, 3 d, that they should carry out a PCM bus system test.

A special PCM bus system test software is then started on the respectively selected modules 2 a, 2 b, 2 c, 2 d, 3 a, 3 b, 3 c, 3 d. This causes the selected modules 2 a, 2 b, 2 c, 2 d, 3 a, 3 b, 3 c, 3 d to output test signals specified by the PCM bus system test software to the PCM bus system 12 b. The b from the PCM bus 12 received response signals are then compared with predetermined response signals, which would have to be received b with correct operation of the PCM bus system 12th If there is a deviation, the corresponding module 2 a, 2 b, 2 c, 2 d, 3 a, 3 b, 3 c, 3 d sends a "fault" signal to the test control device 13 . On the other hand, if the PCM bus system 12 b works correctly from the perspective of the respectively selected module 2 a, 2 b, 2 c, 2 d, 3 a, 3 b, 3 c, 3 d, a “none” is sent to the test control device 13 Error "signal sent.

Next, the test results are evaluated in a test step (IV) in the test control device 13 . The number of faulty tests (number of "error" signals received) is compared with the number of tests carried out (sum of the "error" and "no error" signals). If the ratio between the number of faulty tests and the number of tests carried out exceeds a predetermined threshold value (e.g. the number 0.5, the number 0.7, etc.), the failure unit A (failure unit at the highest level) is Control device 13 marked as "faulty". If the threshold value is undershot, the failure unit A (failure unit at the highest level) is “not faulty” from the perspective of the test control device 13 .

A relatively high number of faulty tests can e.g. B. when the PCM bus 12 b continuously pulled through the module section 4 to ground B. Then come, when b by a defective module section, the functionality of the PCM bus system 12 as a whole disturbed (z. (Og error group X )). In contrast, the number of failed tests z. B. then be relatively low if the error caused by a defective module section belongs to the above error group Y.

If the failure unit A (failure unit at the highest level) is “not defective” from the point of view of the test control device 13 , the bus system test is ended. If, on the other hand, the failure unit A is identified as "faulty", separate tests are carried out in succession in a next test step (IV) for each of the failure units B, C (failure units of the middle level) directly subordinate to the failure unit A. These essentially have the same process steps as described above in connection with the test of the failure unit A (failure unit at the highest level):
First, all module sections 8 , 9 , 10 , 11 that do not belong to the failure unit B that has just been tested (first failure unit in the middle level) are separated from the PCM bus system 12 b. This can e.g. B. happen that the module sections 8 , 9 , 10 , 11 are manually disconnected from the bus system 12 b. Al ternatively z. B. the central test control device 13 by applying appropriate signals to the system control bus system 12 a to separate the module sections 8 , 9 , 10 , 11 from the PCM bus system 12 b.

Next, according to the procedure described above, the central test control device 13 selects those modules 2 a, 2 b, 2 c, 2 d, 3 a, 3 b, 3 c, 3 d, which are the PCM in a parallel manner b bus system 12 to test (in this case all the failure of unit B (first intermediate level) unit failure associated modules 2 a, 2 b, 2 c, 2 d, 3 a, 3 b, 3 c, 3 d). The PCM bus system test software mentioned above is in turn started on the respectively selected modules 2 a, 2 b, 2 c, 2 d, 3 a, 3 b, 3 c, 3 d, which then output appropriate test signals to the PCM bus system 12 b causes. Thereafter, the b from the PCM bus 12 received Ant be word signals with predetermined response signals compared, which would have to be received b with correct operation of the PCM bus system 12th If there is a deviation, the respective module 2 a, 2 b, 2 c, 2 d, 3 a, 3 b, 3 c, 3 d sends an “error” signal to the test control device 13 . Otherwise, a "no error" signal is sent to the test control device 13 .

The test control device 13 next evaluates the test results by comparing the number of faulty tests (number of "error" signals received) with the number of tests carried out (sum of the "error" and "no error" signals) becomes. If the ratio between the number of faulty tests and the number of tests carried out exceeds a predetermined, second threshold value (e.g. the number 0.5, the number 0.7, etc.), the failure unit B (first failure unit middle level) of the Test control device 13 marked as "faulty". If the value falls below the second threshold value, the failure unit B (first failure unit of the middle level) is “not faulty” from the point of view of the test control device 13 .

A corresponding test is then carried out for the failure unit C (second failure unit of the middle level). For this purpose, the module sections 4 , 5 , 6 , 7 , which do not belong to the failure unit C (second failure unit middle level), are separated from the PCM bus system 12 b, and the module sections 8 , 9 , 10 , 11 with connected to the PCM bus system 12 b.

Next, as described above, the central test control device 13 selects those modules which are to carry out a PCM bus system test in parallel (here: all modules belonging to the failure unit C (second failure unit middle level)). The respective selected Mo modules send test completion depending on the test output is a "Def ler" - or a "no error" signal to the test controller. 13

The test control device 13 then compares the number of faulty tests with the number of tests carried out. Depending on whether the ratio between the number of faulty tests and the number of tests carried out is greater or less than a predetermined third threshold value (e.g. the number 0.5, the number 0.7, etc.), the failure unit C ( second failure unit middle level) marked by the test control device 13 as "faulty" or "not faulty".

In the embodiment shown here, for. B. the failure unit B (first failure unit middle level) as "faulty", and the failure units C (second failure unit middle level) as "not faulty" marked the. For the failure unit C, the test is ended. On the other hand, separate tests are carried out successively for all of the failure units B that are directly subordinate to “failure” marked failure units D, E (first and second failure units second lowest level). These essentially have the same method steps as already described above in connection with the tests of the superordinate failure units A, B, C:
First of all module sections 6, 7, 8, 9, 10, 11 are, which is not being tested to failure unit D (first failure unit zweitunterster level), b separated from the PCM bus system 12th Next, according to the procedure described above, modules 2 a, 2 b, 2 c, 2 d of module section 4 and modules 3 a, 3 b, 3 c, 3 d of module section 5 perform in a parallel manner PCM bus system test. The test results are sent to the test control device 13 , again in the form of “errors” or “no errors” signals.

The test control device 13 next evaluates the test results by comparing the number of faulty tests with the number of tests carried out. Depending on whether the ratio between the number of faulty tests and the number of tests carried out is greater or less than a predetermined fourth threshold value (e.g. the number 0.4), the failure unit D (first failure unit, second lowest level) of the test control device 13 is marked as “faulty” or “not faulty”. A corresponding test is then carried out for the failure unit E (second failure unit, second lowest level).

In the invention, it has been recognized that a relatively high chance that an as "failed" Failure unit marked (in this case the module section 4) has a module section belongs, the b, the functionality of the PCM bus system 12 to the total disturb ( Error group X).

Since failure units of higher and then failure units of lower hierarchy levels are tested first, the location of such a module section (here: module section 4 ) is limited with increasing accuracy from test run to test run.

An advantage of the test method described is e.g. B. that it is easily variable to the respective circumstances ten can be adjusted. For example, the size ei one or more threshold values can be changed. alternative or in addition, e.g. B. the number of hierarchy levels be changed. It is also conceivable that the number of module Modify sections that correspond to a particular failure unit are ordered, and / or the module sections to other Aus assign case units as described above.

Claims (9)

1. A method for testing one of several modules ( 2 a, 2 b, 2 c, 2 d, 3 a, 3 b, 3 c, 3 d) shared transmission medium ( 12 b), which comprises the steps:

• 1. Assigning a first group of modules ( 2 a, 2 b, 2 c, 2 d, 3 a, 3 b, 3 c, 3 d) to a first failure unit (D);
• 2. assigning a second group of modules to a second failure unit (E);
• 3. Allocate the modules ( 2 a, 2 b, 2 c, 2 d, 3 a, 3 b, 3 c, 3 d) of the first and second module groups to one of the first and second failure units (D, E) Failure unit (B);
• 4. Testing the parent failure unit (B);
• 5. Testing the first and the second failure unit (D, E), if it was determined in step (c) that the higher-level failure unit (B) is faulty.

2. The method of claim 1, wherein the step (c) carried out test comprises several individual tests, and wherein the higher-level failure unit (B) then viewed as faulty if the relationship between incorrectly ended Individual tests and total individual tests carried out larger than a predetermined threshold. 3. The method of claim 2, further comprising the step of:

• a) changing the predetermined threshold.

4. The method of claim 2 or 3, wherein the predetermined Threshold greater than 0.5 and less than 0.9, in particular is greater than 0.6 and less than 0.8.   5. The method according to any one of claims 2 to 4, wherein a particular module ( 2 a, 2 b, 2 c, 2 d, 3 a, 3 b, 3 c, 3 d) is tested in each individual test. 6. The method according to any one of the preceding claims, wherein the transmission medium ( 12 b) is a bus system. 7. The method according to any one of the preceding claims, wherein the modules ( 2 a, 2 b, 2 c, 2 d, 3 a, 3 b, 3 c, 3 d) are electrical construction groups. 8. The method according to any one of the preceding claims, which further comprises the steps:

• 1. Assigning a third group of modules to a two-th parent failure unit (C);
• 2. Assigning the modules of the first, second and third module group to a main failure unit (A);
• 3. Testing the main fail unit (A);
• 4. Testing the first and the second superordinate failure unit (B, C), if it was determined in step (c1) that the main failure unit (A) is faulty.

9. Test control device ( 13 ) for use in carrying out a test of one of several modules ( 2 a, 2 b, 2 c, 2 d, 3 a, 3 b, 3 c, 3 d) shared transmission medium ( 12 b) according to one of claims 1 to 8, wherein a first group of modules ( 2 a, 2 b, 2 c, 2 d, 3 a, 3 b, 3 c, 3 d) to a first failure unit (D), a second group of modules to a second failure unit (E), and the modules ( 2 a, 2 b, 2 c, 2 d, 3 a, 3 b, 3 c, 3 d) of the first and the second module group to one of the first and the second failure unit (D, E) is assigned to a higher-level failure unit (B), and wherein the test control device ( 13 ) has:

• - Means which cause testing of the higher-level failure unit (B);
• - Means which determine whether the higher-level failure unit (B) is faulty; and
• - Means which cause the first and the second failure unit (D, E) to be tested if it has been determined that the higher-level failure unit (B) is faulty.