JPH0470833B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a simple telephone switching device that accommodates various telephone lines and a plurality of standard telephone sets and provides mutual switching connections.

[Conventional technology]

In such devices, each standard telephone (hereinafter referred to as
A line relay is installed in correspondence with the telephone (telephone), and its operation connects the telephone to the extension circuit, and upon recovery the telephone connects to the telephone line as an outside line. , set the number for each telephone and each number for extension control, and set a separate line capture number. When you dial this number, the line relay is controlled to the outside line, and the telephone is connected to the telephone line. It is assumed that

[Problem that the invention seeks to solve]

However, if there are many calls to outside lines, it is troublesome to dial the outside line locking number each time, and if you want to restrict outgoing calls to a specific phone, you must dial the outside line locking number. Until then, it is unclear whether the telephone in question is the correct one, creating a problem that requires extra operations and time.

[Means for solving problems]

In order to solve the above-mentioned problem, the present invention is constructed by the following means.

That is, in the above-mentioned simple telephone exchange device,
loop detection means for individually detecting off-hook of each telephone; judgment means for determining whether or not an outside call can be made according to the detection power of the loop detection means; The corresponding extension/outside line switching means is brought into a connection state with the telephone line side, and then, depending on the detection power of the extension switching dial by the loop detection means, the extension/outside line switching means is brought into a connection state with the extension circuit side, and the determining means makes a call. and control means for immediately controlling the corresponding extension/outside line switching means to be connected to the extension circuit side when it is determined that the extension/outside line switching means is not possible.

[Effect]

Therefore, when off-hook is performed, it is immediately determined whether or not an outside call can be made, and if it is possible to make an outside line, the connection is made to the telephone line and the outside line is placed in the state of making an outside line. connected to.

Furthermore, if a call cannot be made, the telephone is directly connected to the extension circuit, and the dial tone from the telephone line cannot be heard.

〔Example〕

Hereinafter, details of the present invention will be explained with reference to figures showing examples.

FIG. 1 is a block diagram in which one telephone line 2 from a telephone office or private branch exchange is accommodated as an outside line to line terminals L ₁ and L ₂ of a simple telephone exchange (hereinafter referred to as SEX) 1, and a telephone line 2 is accommodated as an outside line. Terminals T _a1 , T _a2
~T _o1 and T _o2 each have one pair of communication lines 3a to 3n.
A two-wire telephone 4a connected in a star shape by
~4n is accommodated, and telephones 4a and 4c
As shown as a representative circuit, there are telephones 4a to 4n between the telephone line 2 and each communication line 3a to 3n.
Contacts la ¹ , la ² ~ of the corresponding line relays LA ~ LN
ln ¹ and ln ² are respectively inserted as extension/outside line switching means, through which each telephone set 4a to 4n is exchange-connected to the telephone line 2 or an extension circuit to be described later.

However, in this example, telephones 4a and 4b are defined as specific telephones, and these relays
LA and LB are controlled to be in constant operation, and
Contact point la ¹ between telephone line 2 and communication lines 3a, 3b,
Use break contacts for la ² , lb ¹ , and lb ² , and connect relays.
Telephones 4a and 4b are connected to telephone line 2 when LA and LB are restored, but in telephones 4c to 4n other than specific telephones 4a and 4b, relays LC to LN are always in the restored state. Make contacts are used for the contacts lc ¹ , lc ² to ln ¹ , ln ² between the telephone line 2 and the telephone lines 3c to 3n, and the telephones 4c to 4 are controlled by the operation of the relays LC to LN.
n to the telephone line 2.

Further, on the telephone line 2 side from the contacts la ¹ , la ² to ln ¹ , ln ² , a holding circuit including a contact h of a holding relay H and a resistor Rh for opening a DC loop is connected in parallel. An incoming call detection circuit (hereinafter referred to as RDT) 11 is bridge-connected through the contact h, thereby detecting the arrival of a ringing signal from the telephone line 2. , a capacitor Ch, and a transformer Th, a held tone transmission circuit (hereinafter referred to as HTG) 12 consisting of an amplifier, a melody tone generation circuit, etc. is connected.

On the other hand, on the communication lines 3a to 3n side of the contacts la ² to ln ² , there is a non-polar loop detection circuit (hereinafter referred to as LPD) 13 that detects the loop current using a photocoupler or the like.
a~13n and relays FA~FN contacts fa ¹
- fn ¹ are inserted in each one, and ring trip circuits (hereinafter referred to as RTR) 14a to 14n each including a transistor, a resistor, etc. are provided via the contacts fa ¹ to fn ¹ , and the LPDs 13a to 13n,
In addition to detecting the closure of the DC loop and the sending of dial pulses by the telephones 4a to 4n, the RTR
14a to 14n detect the closure of the DC loop when the telephones 4a to 4n respond by going off-hook in response to the sending of the calling signal.

In contrast, a control circuit (hereinafter referred to as
CNT) 15, RDT11, LPD13
A to 13n, RTRs 14a to 14n make control decisions according to the detected power, and each relay H, LA is connected via a relay control circuit (hereinafter referred to as RLC) 16.
~LN, FA~FN control, a ringing signal generation circuit (hereinafter referred to as RGG) 17 that generates a 16Hz ringing signal,
Signal tone generation circuit (hereinafter referred to as TSG) 18, HTG 12, which generates 400Hz dial tone, busy tone, alarm tone, etc.
The switches SW ₀ , SW _a1 , SW _a2 to SW _o1 , SW _o2 are controlled using analog switch circuits, etc., and exchange connections are thereby performed.

In addition, in order to regulate the incoming and outgoing calls, etc., a regulation setting circuit (hereinafter referred to as
RST) 19 is provided, and the situation of this is CNT1
5 is checked to determine whether exchange connection is possible.

However, a commercial power supply is used as the main power supply for SEX1, and a local DC power supply V is supplied to each part by a power supply circuit not shown in the diagram, and a large capacitor is installed in the power supply circuit. Prepare,
In the event of a main power outage, the local power supply V can continue to be supplied for a certain period of time.

In addition, CNT15 puts the relays LA and LB into the operating state when the main power supply is energized, and puts them into the recovery state at the time of a main power outage or as necessary.
LC to LN are always in a recovery state and are in an operating state when necessary, and when energized, the telephones 4a to 4n connect through contacts la ¹ , la ² to ln ¹ , ln ² ,
A communication current supply circuit (hereinafter referred to as
TFC) 20a to 20n, respectively.

Therefore, if an off-hook call is made from any telephone 4, this will be called from the LPD 13.
When the CNT 15 determines the calling telephone and checks the RST 19 to allow an outside call, it restores the relays LA and LB for the telephones 4a and 4b, and switches the telephones 4c to 4n.
If so, operate relays LC~LN and connect telephone line 2.
to make an outside call.

Then, when a dial call is made, the
If detected by the LPD 13 and it is a series of external line calling numbers, the CNT 15 continues the above-mentioned external line connection control, but if it is a single digit extension acquisition number,
It is determined that this is an extension switching dial, and the relays LA and LB are restarted, or the relays LC~LN are restored, and a switching decision is made depending on the extension number that is called next, and RGG17 and relays LA~
Corresponding ones in LN, as well as relay FA~
Controls the corresponding in FN, protects the called telephone with protective resistor Rr and contacts fa ² ~ fn ² , fa ¹ ~ fn ¹
The RGG 17 and RTR 14 are connected through the telephone, and a ringing signal with the local power supply V superimposed thereon is sent out, so that the tone ringer of the called telephone rings to notify the incoming call.

In response, when the called telephone responds by going off-hook, the RTR 14 detects the loop closure, and the CNT 15 relays accordingly.
In order to control the corresponding ones in FA to FN and turn on the ones corresponding to the calling side and the called side among switches SW _a1 to SW _o1 , an extension circuit via a capacitor Ct and a resistor Rt is connected. Completed, TFC
An extension call is made by the current from 20.

In addition, depending on switches SW _a2 to SW _o2 being turned on, dial tone, busy tone, ringing tone, etc. are transmitted from the TSG 18, and depending on switch SW ₀ being on, the amplifier input in the HTG 12 is transmitted. toTSG1
By simultaneously operating the relay H, an alarm sound or the like is sent to the telephone 4 during an outside line call.

In addition, in the case of an outside call, the LPD 13 detects the loop current from the exchange regardless of the line voltage polarity on the telephone line 2 side, and if the loop current is disconnected due to on-hook due to the end of the call, In response to this detection power disappearing, CNT15 relay LA
- The corresponding one in LN is connected to the extension circuit, and the telephone line 2 is opened.

In contrast to the above, incoming calls from telephone line 2 are RDT
11, and CNT15 is detected accordingly.
In order to control RGG 17 and relays LA to FN and simultaneously send a ringing signal to each telephone 4a to 4n, each tone ringer rings at the same time, and if any telephone 4 responds, the telephone line 2 You can connect to and answer calls freely.

In addition, if you want to set a hold state for the purpose of transfer etc. during a call to telephone line 2, for example, if you dial "0",
Since CNT15 controls relay H and HTG12, a hold loop is closed by contact h, a hold tone is sent from HTG12, and once on-hook is performed, for example, if you dial "0" again, , the hold status is to be released.

In addition, if a power outage occurs in the main power supply, all relays will be restored and extension calls will be impossible, but contacts la ¹ , la ² , lb ¹ , and lb ² will be connected to telephone line 2 by turning on the break contacts. Since the telephones 4a and 4b are connected to each other, they can be used to make and receive calls to outside lines even during power outages, whereas the other telephones 4c to 4
n is disconnected from the telephone line 2 by turning off the make contacts of the contacts lc ¹ , lc ² to ln ¹ , ln ² , and only the two telephones 4 a and 4 b are connected in parallel to the telephone line 2 . The state will be as follows.

In addition, when any of the telephones 4 goes off-hook, the CNT 15 checks the RST 19 to determine whether or not the telephone is set to restrict outside calls, and also determines whether or not the telephone line 2 is in use. Check to determine whether it is possible to make an outside call,
If this call is possible, it will be connected to an outside line, and if the extension acquisition number is not dialed, it will remain connected to the outside line, but if it is not possible to make an outside call, it will immediately connect to the extension circuit and make a call from TSG18. A sound is sent out to notify that the telephone is only permitted to make calls to extensions.

Figure 2 shows the processor (hereinafter referred to as
This is a flowchart of the control status by CPU).
“Loop monitoring” 10 using the detection power of LPD13
1 and this is "Loop NO?" 102 Y
(YES), checks the "Status on-hook?" 103 according to the status data of the telephone 4 stored in the memory in the CNT 15, and if this is Y, it is determined that it is a new off-hook, and then 111 “Incoming call on external line?” 111 according to the detection power of RDT 11, 112 “Is the telephone in question receiving an extension call?” 112 in accordance with the memory contents of CNT 15, 113 “In use on external line?” 113, and “Incoming telephone Restrictions on making outside calls?”1
14 in sequence, and if both are N (NO), perform 121 "Set the status to off-hook/external line call" for the relevant telephone, and then "control to the corresponding line relay/external line side" with the relevant telephone. ”1
24, connect the telephone to telephone line 2,
Step 101 and subsequent steps are repeated.

Therefore, if the telephone line 2 is empty, no outside line call restriction is set for the telephone, and an outside call can be made, the telephone is immediately connected to the telephone line 2.

On the other hand, if step 113 is Y or step 114 is Y, ``set status to extension call'' 131 is performed, and then ``send dial tone to the telephone in question'' 132 is performed.

Therefore, if outside call restriction is set or if telephone line 2 is in use, the telephone will remain connected to the extension circuit and the dial tone from SEX1 will not be heard.
Since it is given from TSG18, it is possible to know whether it is impossible to make an outside call.

If step 111 is Y, the process goes to "external line response process" 141, and if step 112 is Y, the process goes to "extension line response process" 142, and if step 102 is N, the process goes to "other applicable process". 151, detects an extension switching dial in response to dialing an extension acquisition number, and controls the connection of the telephone to the extension circuit side accordingly.

Therefore, once the external line is connected in step 122, if you dial the extension acquisition number, you will be connected to the extension circuit.
Further, when the telephone number of the called party is dialed, an extension call is made as described above.

However, instead of using a pulse dial signal, a complex audio frequency dial signal is used to make the receiver
The present invention may be provided in the SEX 1, or the same may be applied to a plurality of telephone lines 2 and the present invention applied to each line, and the present invention can also be applied to a button telephone device containing a plurality of two-wire telephones.

In addition, relays LA to LN may be set in the external line connection state from the beginning, and even if the relays LA to LN are in a silent state without sending out a dial tone after connection to the extension circuit, connection to the extension circuit can be determined, and relays LA to
Various modifications are possible, such as replacing LN with another switching element.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, the connection is made to the telephone line in response to off-hook and with the premise that outside calls can be made, so outside calls can be made immediately, and the dialing signal of the lost outside line number can be omitted. If it is not possible to make an outside call, the connection is immediately made to the extension line, so this can be quickly determined, and a significant effect can be obtained in a simple telephone exchange.

[Brief explanation of the drawing]

The figures show an embodiment of the present invention, with FIG. 1 being a block diagram and FIG. 2 being a flowchart of the control situation. 1...SEX (simple telephone exchange), 2...telephone line, 3a-3n...talk line, 4a-4n...telephone (standard telephone), 13a-13n...LPD
(loop detection circuit), 15...CNT (control circuit),
18...TSG (signal tone generation circuit), 19...RST
(Regulation setting circuit), 20...TFC (talking current supply circuit), LA~LN...Relay (line relay), la ¹ ,
la ² ~ln ¹ , ln ² ...Contact, SW _a1 , SW _a2 ~ _{SW o1} ,
SW _o2 ...Switch.

Claims (1)

[Claims] 1. Accommodates a telephone line and a plurality of standard telephones connected in a star shape, and individually connects each of the standard telephones to the telephone line side and the extension circuit side through extension/external line switching means corresponding to each standard telephone. In a simple telephone exchange device for making exchange connections, a loop detecting means for individually detecting off-hook of each standard telephone, a determining means for determining whether or not an outside call can be made according to the detection power of the loop detecting means, and the determining means When it is determined that it is possible to make a call, the switching means corresponding to the detected power is connected to the telephone line side, and then the switching means is connected to the extension circuit side according to the detected power of the extension switching dial by the loop detecting means. and control means for immediately controlling the corresponding switching means to connect to an extension circuit side when the determining means determines that a call cannot be made.