JPS6336705B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a test connection method, and particularly to a test connection method in a test device that draws in a plurality of types of communication lines housed in an automatic exchange and tests the line side and the automatic exchange side of the communication lines. FIG. 1 is a diagram showing an example of a conventional test connection method in this type of test equipment. In Figure 1, the automatic exchange EX has a central office line COL and a DC trunk line.
Various communication lines such as LDL, 2-wire carrier line 2WODL, and 4-wire carrier line 4WODL are accommodated via the distribution frame MDF. The distribution board MDF has test jacks Ji (i is 0, 1,
2 and 3) are provided, and the test equipment TST
By inserting the test plug TP into the test jack Ji of the communication line to be tested, the communication line is connected to the test equipment TST, and the communication line is connected to the central office line trunk COT, LD trunk LDT, 2-wire OD trunk 2WODT, or 4-wire OD trunk. The configuration allows for separate testing of the automatic exchange EX side, which includes 4WODT and network NW, and the line side. Now DC relay line
When testing LDL, use the trunk test circuit TTC and line test circuit LTC in the test equipment TST.
is set in advance to match the DC trunk line LDL to be tested by operating an electric key (not shown). Next, the tester connects the test plug TP to the DC relay wire.
When inserted into test jack J1 corresponding to LDL,
The DC trunk line LDL is drawn into the connecting test device TST by the contacts tt and lt of the relays TT and LT which are in the recovery state. Next, the examiner pressed the phone key.
When KM is operated, relay MON operates and connects DC trunk line LDL to monitor circuit MOC. Therefore, the tester can identify the usage state of the DC trunk line LDL, that is, whether it is busy or idle.
When the tester confirms the free status of the DC trunk line LDL and operates the telephone key KT, the relay TT operates, disconnects the DC trunk line LDL, connects the LD trunk LDT to the trunk test circuit TTC, and connects the automatic switchboard. EX
side test becomes possible. Similarly, if the tester
When KL is operated, relay LT operates and DC relay line
Testing on the line side is possible by connecting LDL to the line test circuit LTC. As is clear from the above explanation, according to a conventional test connection method, the connection of the communication line under test (in this case, the DC trunk line LDL) to the test equipment TST is as follows:
Everything depends on the tester's judgment and operation. Therefore, for example, if the tester inserts the test plug TP into the test jack J1 while operating the telephone key KT or KL, there is a risk of accidentally disconnecting the DC trunk line LDL during a call. In addition, if the test jack J3 is inserted when it should be inserted into the test jack J1, the line test circuit LTC, which is set for the DC trunk line LDL, will damage the terminal equipment of the four-wire carrier line 4WODL. Fear also arises. In addition to the above, erroneous operation by the tester may cause damage to the trunk line under test or the test equipment TST. An object of the present invention is to realize a test connection method that eliminates the drawbacks of the conventional test connection methods as described above and prevents damage caused by erroneous operation by a tester. The purpose of this is to provide a test equipment that connects multiple types of communication lines accommodated in an automatic exchange and tests the line side and the automatic exchange side of the communication line.
A potential detection means is connected to a filament determined according to the type of the communication line to be tested via the connection means used for the lead-in, and the potential of the filament is set to a predetermined potential. This is achieved by identifying the communication line by the potential detecting means, thereby confirming that it is the intended communication line and that the communication line is in an idle state, and then pulling in the communication line. An embodiment of the present invention will be described below with reference to FIGS. 2 and 3. FIG. 2 is a diagram illustrating a test connection scheme according to an embodiment of the present invention. In Figure 2, various communication lines such as the central office line COL, DC relay LDL, 2-wire carrier line 2WODL, and 4-wire carrier line 4WODL are equipped with test jacks Ji (i is 0 to 3) as in Figure 1. It is housed in the automatic exchange EX via the distribution board MDF. Now DC relay line
When conducting an LDL test, the tester must first test the trunk test circuit of the test device TST', as shown in Figure 1.
After setting the TTC and line test circuit LTC to match the DC trunk line LDL to be tested, insert the test plug TP into the test jack J1. In the test device TST', a verification circuit CHK is connected to the DC trunk line LDL which is connected and connected.
The verification circuit CHK identifies the type and usage status of the connected communication line without disturbing the communication line, and determines whether the communication line type is the DC trunk line LDL to be tested and whether it is in an idle state. When something is identified, the verification output relay G is operated. When the tester operates the electric key KT or KL while the verification output relay G is activated, the relay
Since TT or LT operates and maintains itself, the first
As in the figure, it is possible to test the automatic exchange EX side using the trunk test circuit TTC, or test the DC trunk line LDL using the line test circuit LTC. If the drawn-in DC trunk line LDL is busy or if it is accidentally inserted into the test jack Ji of another type of communication line, the verification circuit CHK will not operate the verification output relay G. The tester accidentally used the telephone key.
Even if you operate KT or KL, relay TT and
LT does not operate, and there is no risk of cutting off the communication line that has been drawn in. Next, an example of the matching circuit CHK in FIG. 2 will be explained with reference to FIG. 3. In FIG. 3, only the DC trunk line LDL and the four-wire carrier line 4WODL are shown. Test jacks J1 and J3 are both 6-wire (A to F)
jack is used. Therefore, the two-wire DC trunk line LDL is connected to one test jack J1.
Three DC trunk lines LDL#0 to LDL#2 are accommodated in the . On the other hand, only one line of the four-wire transport line 4WODL, which requires six lines including the signal line, is accommodated in one test jack J3. Focusing on DC trunk line LDL#0, when it is empty, wire A has -48 volts and wire B has an earth potential of LD trunk.
The potentials V _A and V _B of the filament A and filament B each exhibit an intermediate value between the earth potential and -48 volts due to the loop that is supplied from the LDT #0 and is created in the DC trunk line LDL #0 in the busy state. . DC trunk line LDL
#1 filament C and filament D, and DC relay line
The potentials of striae E and striae F of LDL#2 change similarly. On the other hand, when focusing on the 4-wire transport line 4WODL, filaments A, B, C, and D are not supplied with DC potential regardless of the usage state, and when the wire E is idle, the 4-wire transport line 4WODL (carrier terminal station DC potential -VD (<-48 volts) is supplied from the
In busy state, 4-wire OD trunk 4WODT contact
dl operates and earth potential is supplied. Also, when the wire F is empty, it is from the 4-wire OD trunk 4WODT.
48 volts are supplied, and in the busy state, the contact γg of the 4-wire carrier line 4WODL (carrier terminal unit) is activated to supply ground potential. The test jack J mentioned above
The table shows changes in the DC potential of each of the filaments A to F of No. 1 and J3 depending on the usage conditions. Meanwhile testing equipment
The matching circuit CHK of TST′ is the −48 volt comparator CMP
and illustrated

[Table] The type selection relays LD0, LD1, LD2 and OD are included. Now select the DC trunk line LDL#0 as the test target, and insert the test plug TP into the test jack J1 while operating the type selection relay LD0 of the verification circuit CHK. The test jack J1
The wires A to F housed in Only row A is connected to the -48 volt comparator CMP via active contact Id0. -
The 48 volt comparator CMP operates the verification output relay G when -48 volts is continuously input for a predetermined period of time. Therefore, if the DC trunk line LDL#0 is in an empty state, -48 volts is input from the line A as described above, and the verification output relay G operates the verification circuit CHK. If the DC relay LDL#0 is busy, -V _A (>-48 volts) from wire A.
is input, the verification circuit CHK does not operate the verification output relay G. In addition, the DC trunk line LDL
Even if -48 volts is supplied from wire A for a short time while #0 is sending dial pulses, the -48 volt comparator
Due to the time-limited characteristics of CMP, verification output relay G does not operate. Even if the tester accidentally inserts the test plug TP into the test jack J3, the verification circuit CHK operates the verification output relay G because no DC potential is input from the wire A of the 4-wire transport line 4WODL. There's nothing to do. On the other hand, the verification circuit CHK is a line A
It is connected to filament A without connecting to anything other than -48
The input impedance of the volt comparator CMP is also maintained at a sufficiently high impedance, so the 4-wire carrier line 4WODL and the DC trunk line in the busy state are
It does not interfere with LDL#0 in any way. As is clear from the above explanation, according to this embodiment, the test device TST' which tests the DC trunk line LDL#0 connects the high impedance -48 volt comparator CMP only to the wire A of the test plug TP. Therefore, the verification output relay G operates only when the DC trunk line LDL#0 is in an empty state, and the subsequent test operation becomes possible. Other DC trunk lines LDL
#1, LDL #2 and 4-wire carrier line 4WODL
Verification output relay G also does not operate, and does not cause any interference. Note that FIGS. 2 and 3 are only one embodiment of the present invention, and for example, the test object is not limited to the DC trunk line LDL#0 in FIG.
The effects of the present invention do not change even in the case of other DC trunk lines LDL#1, LDL#2 or four-wire carrier line 4WODL. Furthermore, the configuration of the verification circuit CHK is not limited to the DC trunk lines LDL#0, LDL#1, LDL#2 and the 4-wire carrier line 4WODL, but can also be used for other types of communication lines. Even in this case, the effects of the present invention remain unchanged. As described above, according to the present invention, the test operation of the test device is valid only when the communication line to be tested is in an idle state, and due to the tester's erroneous operation, a busy communication line and a communication line not to be tested are This prevents damage from occurring.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of a conventional test connection method, FIG. 2 is a diagram showing a test connection method according to an embodiment of the present invention, and FIG. 3 is a diagram showing an example of the verification circuit in FIG. 2. . In the figure, EX is an automatic exchange, NW is a network, COT is a central office trunk, LDT, LDT
#0, LDT#1 and LDT#2 are LD trunks,
2WODT is 2 wire OD trunk, 4WODT is 4
Wire OD trunk, COL is central line, LDL, LDL
#0, LDL#1 and LDL#2 are DC relay lines,
2WODL is a 2-wire carrier circuit, 4WODL is a 4-wire carrier line, MDF is a distribution board, J0, J1, J2 and J3 are test jacks, TP is a test plug,
TST and TST' are test equipment, TTC is trunk tester, LTC is line tester, MOC is monitor circuit, CHK is verification circuit, CMP is -48 volt comparator, G is verification output relay, TT, LT and MON
is a relay, KT, KL, and KM are electric keys, dl and γg are relay contacts, ld0, ld1, ld2, and od are contact points of type selection relays, and A, B, C, D, E, and F are wires.

Claims (1)

[Claims] 1. In a test device that connects multiple types of communication lines accommodated in an automatic exchange and tests the line side and the automatic exchange side of the communication line, the above-mentioned A potential detection means is connected via a connection means used for lead-in, and the potential detection means identifies that the potential of the filament is set to a predetermined potential, thereby establishing the desired communication line. A test connection method characterized in that the connection is made after confirming that the communication line is empty and that the communication line is idle.