JPH0715548A - Call reception function changeover device - Google Patents

Abstract

PURPOSE:To output a command for various setting depending on the presence of an incoming call by providing a changeover means selecting a mode transiting immediately to line acquisition on the reception of an incoming call or a mode transiting by an incoming call connection command after the command received in the changeover device. CONSTITUTION:When a call signal comes from a line, a call indication (CI) signal 109 is set to a data terminal equipment (DTE) 120 from a data line terminator (DCE) 101 to inform the presence of the incoming call. When the DTE 120 commands the call reception to the DCE 101 by setting a data terminal ready (ER) signal 111 in an ON state, the DCE 101 makes a reply to the DTE 120. Then the line is acquired immediately. On the other hand, suppose that an incoming call is received while the DIC mode is set to the DCE 101, then the DCE 101 sets the CS signal to informs the DTE 120 of the DIC mode. Upon the receipt of an incoming call connection (CIC) command from the DTE 120, the DCE 101 acquires the line.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an incoming call function switching device for making an incoming call using a network control device or a modulation / demodulation device having a built-in network control function.

[0002]

2. Description of the Related Art As a conventional incoming call function switching device, an IT
U (INTERNATIONAL TELECOMMU
NICATION UNION: CCITT (THE INTERNAT), an organization under the umbrella of the International Telecommunication Union
IONAL TELEGRAPH AND TELEP
HONE CONSULTIVE COMMITT
EE: International Telegraph and Telephone Advisory Committee) Recommendation V.3 in the V series Recommendations that summarizes the recommendations for data communication in the telephone network. 25bis, "Automatic calling and answering device in a general switched telephone network using 100 series interconnection circuits".
It has been known.

In the above "automatic calling and answering device in the general switched telephone network using the 100 series interconnection circuit", the data circuit terminating device (DCE) is such that the data terminal device (DTE) sends an ER signal when there is an incoming call. When the DIC command is not sent from the DTE to the DCE within the period stipulated by the domestic regulations after turning ON, or when the CIC command is sent following the DCE command sent within this period. , Shift to track acquisition.

Next, the case where the DIC command is not sent from the DTE to the DCE within the period defined by the domestic regulations will be described.

FIG. 25 shows DTE and DC when there is an incoming call.
The flow of various signals between E is shown.

First, if there is a ringing signal from the telephone network in 701, the DCE notifies the DTE of the incoming call by the CI signal in 702, and if the incoming call is received, the D in 703.
The TE turns on the ER signal to the DCE, and the DCE responds to the DTE by turning on the CD signal to the DTE, and further returns the INC indication to the DTE at 705. 706 that the CS signal is turned on in 706 and the command can be accepted from the DCE.
Let E know.

Thereafter, if the DIC command is not sent from the DTE to the DCE within the fixed period 707, the fixed period 70
After lapse of 7 seconds, capture the line at 708 (same meaning as loop closure)
I do.

Next, the case where the CIC command is sent following the DIC command will be described.

FIG. 26 shows DTE and DC when there is an incoming call.
The flow of various signals between E is shown.

801 to 806 are 70 in FIG.
The description is omitted because it is the same as 1 to 706. After that, if a DIC command is sent from the DTE to the DCE at 808 within a certain period of time 807, at 809 the DCE responds to D
VAL indication is returned to TE, line acquisition is suspended, and after that, CI is transmitted from DTE to DCE at 810.
If C command is sent, DCE for it at 811
Returns a VAL indication to DTE and performs line acquisition at 812.

In the period 813 from 809 to 810, D
The TE can set various modes to the DCE with commands. Conversely, when the DTE wants to set various modes for the DCE when receiving a call, the DTE is set within the period 807.
IC commands must be sent from the DTE to the DCE to temporarily suspend line acquisition.

25 and 26, the ringing signal is repeated ON / OFF, the CI signal is also repeatedly turned ON / OFF, and the interval can be changed by the operation on the exchange side. For example, in a private branch exchange, ON can be repeated for 1 second and OFF for 1 second for an incoming call from an outside line, and ON for 1 second and OFF for 2 seconds for an incoming call from an extension line. But this is
It is not used in connection with the above two cases.

[0013]

In the above-mentioned conventional technique, even when the DTE at the time of incoming call does not need to set various modes for the DCE, it waits for a certain period of time, or the DIC command and the CIC command follow. If you do not send
Since there is no transition to line acquisition, there is a problem that a certain amount of time elapses until line acquisition even if there is an incoming call when it is not necessary to set various modes.

On the contrary, when it is desired to set various modes, the DIC command is changed from DTE to DC within a certain period.
Must be sent to E, which can be difficult for the DTE at that time. For example, when the DTE has a low capability, if most of the capability is used for other processing when there is an incoming call, there is a problem that the command may not be sent within a certain period.

Further, when the DCE is connected to a private branch exchange, there may be an incoming call from an outside line and an incoming call from an extension line. Then, for both of these incoming calls, the DTE
There is a problem in that even if the contents of various mode settings given to E cannot be changed, they cannot be changed.

In view of the problems of the above-described conventional incoming call function switching device, an object of the present invention is to output various setting commands depending on the presence / absence of an incoming call, and when it is not necessary to output various setting commands. Another object of the present invention is to provide an incoming call function switching device that can immediately capture a line and can perform a plurality of types of processing separately according to the time interval of a CI signal.

[0017]

SUMMARY OF THE INVENTION An object of the present invention is to provide, in a predetermined method, a mode of immediately shifting to line acquisition when an incoming call is received and a mode of shifting to line acquisition by an incoming call connection command after receiving a command. This is achieved by an incoming call function switching device having switching means for switching based on the above.

Another object of the present invention is to measure incoming and outgoing time intervals of a called table signal, and to select various settings such as a transmission and reception level according to the type of the measured time intervals. It is also achieved by a function switching device.

Further, an object of the present invention is to measure the time interval of turning on and off of the called table signal and to select a command to be output later according to the kind of the time interval measured. It is also achieved by a function switching device.

[0020]

In the incoming call function switching device of the present invention, the switching means is
When an incoming call is received, a mode of immediately shifting to line acquisition and a mode of transitioning to line acquisition by an incoming call connection command after receiving a command are switched based on a predetermined method to flexibly switch the mode at the time of incoming.

Further, in the incoming call function switching device of the present invention, the selecting means measures various time intervals of turning on and off of the called table signal and selects various settings such as a transmission / reception level according to the kind of the time interval measured. .

Further, in the incoming call function switching device of the present invention, the selecting means measures the time interval of ON / OFF of the called table signal, and selects the type of command to be output thereafter according to the type of the time interval measured. .

[0023]

[Embodiment] In the following, the former mode of immediately shifting to line acquisition is called the CIC mode, and the latter CIC command is DIC.
The mode in which the CE accepts the line after receiving it is called the DIC mode. And these two modes will be simply called CIC / DIC mode below.

An embodiment of an incoming call function switching device of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a first block diagram of the incoming call function switching device of the present invention.
It is a block circuit diagram which shows the structure of an Example.

The incoming call function switching device of FIG. 1 is connected to a data circuit terminating device (DCE) 101, DCE 101 which mainly performs modulation and demodulation of an input signal and control thereof, and immediately receives an incoming call. It is configured by an incoming call function switching device including a data terminal device (DTE) 120 that is a switching means for switching between a mode for shifting to line acquisition and a mode for shifting to line acquisition by an incoming call connection command after receiving a command based on a predetermined method. Has been done.

DCE is a network control unit (NCU)
It is a collective name for a modem (MODEM) that has a built-in NCU function.

The DCE 101 is a central processing unit (CPU) 102 that controls the entire DCE 101, a read only memory (ROM) 103 that is connected to the CPU 102 and stores a control program of the CPU 102, and a CPU 1.
Random access memory (RAM) 10 connected to the CPU 02 and used by the CPU 102 as a work area
4, an incoming call detection unit 105 connected to the CPU 102 for detecting an incoming call, a level adjustment A for adjusting the transmission level
A TT (attenuator) 106, a connector 107 that is connected to the CPU 102 and is a connection portion with the DTE 120,
A power supply 108 for supplying power to each unit inside the DCE 101,
The modulation / demodulation control circuit unit 109 is connected to the CPU 102 and the level adjusting ATT 106 and performs modulation, demodulation, and control of the input signal.

The modulation / demodulation control circuit section 109 is composed of a modulation section, a demodulation section, a folding section, etc. as shown in FIG. 2, but since it is not directly related to the present invention, it is only shown in the figure.

Next, each of the above components will be described in detail.

DCE 101 to D are connected to the connector 107.
Called indication (CI) signal 109 indicating that the DCE 101 is receiving the called signal on the TE 120, and data channel reception indicating that the line signal of the data receiving channel of the DCE 101 is in the prescribed range from the DCE 101 to the DTE 120. Carrier detect (CD) signal 110, DTE
120 to the DCE 101, the data terminal ready (ER) signal 111 indicating that the DTE 120 is ready for operation or instructing the line acquisition, and the DCE 101 to the DTE.
120 to the data set ready (DR) signal 112, DTE12 indicating that the DCE 101 is ready for operation
0 to DCE 101 Transmission request (RS) signal 113, DCE1 requesting that DCE 101 enter transmission mode
01 to DTE 120 DCE 101 is ready to send (CS) signal 114, DTE 12
0 to DCE101 Indicates the data to be transmitted to the remote communication partner, or DTE120 to DCE101 to DCE
A transmission data (SD) signal 115, which indicates an instruction (hereinafter, referred to as a command) that defines the operation mode of E101, DC
E101 to DTE120 Indicates data transmitted from a remote communication partner, or DCE101 to DTE12
There is a reception data (RD) signal 116 indicating a status (hereinafter, referred to as an indication) indicating the state of the DCE 101 to 0.

DC signal from DTE 120 with SD signal 115
Among the commands sent to 101, those related to the present invention are an incoming call invalidation (DIC) command that instructs to ignore the called signal and not to receive, and to enable the called signal to allow the incoming call. There is an incoming call connection (CIC) command to direct.

Further, among the indications sent from the DCE 101 to the DTE 120 by the RD signal 116, what is relevant to the present invention is that a valid (VAL) indication indicating that the command is valid and a called signal are detected. There is an incoming call (INC) indication indicating.

Next, the incoming call detecting section 105 is a circuit for detecting an incoming call on the telephone line, and the power required for its operation is supplied from the telephone line. Therefore, it is not necessary to receive the power supply from the power supply 108.

Although the level adjusting ATT 106 is not an element necessary for the configuration of the present invention, it is described for explaining the advantages of the present invention, which is the CPU 10.
The level is adjustable from 2.

The DTE 120 is a device that is connected to the DCE 101 and controls the DCE 101. Below, D
The configuration of the TE 120 will be described.

The DTE 120 is connected to the CPU 121 and the CPU 121 that control the DTE 120 as a whole, and the CP
ROM 122, C for storing the control program of U121
A RAM 123 connected to the PU 121 and used by the CPU 121 as a work area, and an input device 12 connected to the CPU 121 and receiving external data input.
4, the output device 125 that is connected to the CPU 121 and outputs data to the outside, is arranged between the DCE 101, and is connected to the CPU 121.
Level conversion of data potential difference between the CE 101 and serial / parallel conversion (generally, data is handled as parallel data inside the DTE 120 and serially inside the DCE 101 and the telephone line. Modem NCU interface 126 for
A connector 127, which is connected to the modem NCU interface 126 and is a connection portion with the DCE 101, a DTE
The power source 128 is configured to supply power to each unit inside 120.

Each signal of the connector 127 is supplied to the DCE 101.
One-to-one correspondence with each signal of the connector 107.

The power supply 128 is turned on / off by DT
This can be done with the power switch provided in the E120, but by using the switch circuit 129, the CI from the DCE 101 can be
The signal 109 can also be turned on. That is, when there is an incoming call, the incoming detection unit 105 of the DCE 101 detects this, and the DTE 120 outputs the CI signal 109.
Can be turned on. Then, the CI signal 109
Since the power is supplied from the telephone line connected to the DCE 101, it can operate even if the power is not supplied to the entire DCE 101.

FIG. 3 shows a second embodiment of the incoming call function switching device of the present invention.
The structure of an Example is shown.

In the following embodiments, only the differences from the configuration shown in FIG. 1 will be described.

The difference between the incoming call function switching device of FIG. 3 and the incoming call function switching device of FIG. 1 is that the AC power source 208 of the DCE 201 is
That is, it is linked with ON / OFF of the power supply 228 of the DTE 220. That is, if the power supply 228 is turned on to the DTE 220, the power supply 208 of the DCE 201 is also turned on, and the DTE 220 is turned on.
When the power source 228 of the DCE 201 is turned off, the power source 208 of the DCE 201 is also turned off.

FIG. 4 shows a third embodiment of the incoming call function switching device of the present invention.
The structure of an Example is shown.

The difference from FIG. 1 is that the DCE 301 does not have its own power source, but the power source line 317 of the connector 307
Power is supplied from the power supply 328 of the DTE 320. Therefore, the power source of the DCE 301 is interlocked with ON / OFF of the power source 328 of the DTE 320. That is, DTE32
If the power supply 328 of 0 turns on, the power of the DCE 301 also turns on, and if the power supply 328 of the DTE 320 turns off, DCE
The power of 301 is also configured to be turned off.

FIG. 5 shows a fourth embodiment of the incoming call function switching device of the present invention.
The structure of an Example is shown.

The difference from FIG. 1 is that a switch 418 is provided inside the DCE 401 and the switch 418 is turned on / off.
That is, the CPU 402 is configured so that the CPU 402 can freely detect (sense).

FIG. 6 shows a fifth embodiment of the incoming call function switching device of the present invention.
The structure of an Example is shown.

The difference from FIG. 3 is that a switch 518 is provided inside the DCE 501 and the switch 518 is turned ON / OF.
That is, the CPU 502 is configured to freely sense the F state.

FIG. 7 shows a sixth embodiment of the incoming call function switching device of the present invention.
The structure of an Example is shown.

The difference from FIG. 4 is that a switch 618 is provided inside the DCE 601, and this switch 618 is turned ON / OF.
That is, the CPU 602 is configured to freely sense the F state.

(A) Next, regarding the configuration of the embodiment shown in FIGS. 1, 2, 3, and 4, referring to FIGS. 8 and 9, the flow of various signals in the CIC / DIC mode will be described. , Referring to the flow chart of FIG.
Each will be explained.

FIG. 8 shows a C or C in ROM or RAM of DCE.
7 shows the flow of various DCE-related signals when there is an incoming call when the IC mode is set.

First, if there is a ringing signal from the line at 901, the CI signal is turned on from DCE to DTE at 902.
If the incoming call is instructed by turning on the ER signal from the DTE to the DCE at 903, the DCE turns on the CD signal to the DTE at 904. Then, in 905, the DCE responds to the DTE with an INC indication. Immediately thereafter, the line is captured at 906. DTE
It can be seen that the side is in the CIC mode because the CD signal does not turn ON after the INC indication.

FIG. 9 shows D in ROM or RAM of DCE.
7 shows the flow of various DCE-related signals when there is an incoming call when the IC mode is set.

Since 1001 to 1005 are the same as 901 to 905 in FIG. 8, the description thereof will be omitted.

At 1006, the DCE turns on the CS signal to notify the DTE that it is in the DIC mode and that the command can be accepted.

Thereafter, if the DTE sends a CIC command to the DCE at 1007, the DCE
Returns a VAL indication to the DTE at 1008 and captures a line at 1009.

Then, in the period 1010 from 1006 to 1007, the DTE can set various modes to the DCE by commands.

Next, the operation on the DCE side will be described with reference to the flowchart of FIG.

First, at 1101, wait for a call signal from the telephone network, and at 1102, if there is this call signal, CI
Turn on the signal to notify the DTE. Wait at 1103 for the DTE to turn on the ER signal. If this signal turns on at 1104, turn on the CD signal to notify the DTE. 1
At 105, the INC indication is then returned to the DTE, and at 1106, it is determined whether the CIC / DIC mode set in the ROM or RAM of the DCE, 11
If it is 07 in DIC mode, turn on the CS signal and
Waiting for various commands from DTE at 08, if a command is received at 1109, it is judged whether the command is a CIC command, and if it is a CIC command at 1110, V
The AL indication is returned to the DTE, and the line is captured at 1111. If it is not a CIC command in 1109, the command is executed in 1112, and then the process returns to 1108 and waits for a command again. In addition, the above 11
In the CIC mode at 06, the process immediately proceeds to 1111 and the line is captured.

That is, in the configurations shown in FIGS. 1, 2, 3 and 4, all are based on the mode (CIC mode or DIC mode) set in the ROM 103, 203, 303 or RAM 104, 204, 304. , C
The PUs 102, 202, 302 have the incoming call detection units 105, 20.
When the call signals from the Nos. 5 and 305 are detected, the respective units are controlled according to the above-described FIGS. 8, 9, and 10.

Therefore, according to the above-mentioned configuration, there are provided two modes, that is, a mode in which the line is immediately acquired when there is an incoming call, and a mode in which the line is acquired by the CIC command after receiving the command. This allows DTE when there is an incoming call.
If there is no need to issue various setting commands to the DCE, it is possible to immediately shift to line acquisition, and conversely, if various setting commands need to be issued, there is a fixed period of time before command reception. Since it is eliminated, various setting commands can be issued to the DCE even if the DTE has a low processing capacity.

Furthermore, when there is an incoming call, the R inside the DCE
The CIC / DIC mode can be switched by the setting in the OM or RAM.

(B) Next, regarding the configuration of FIGS. 1, 2, 3 and 4, with reference to FIGS. 11 and 12, CIC
The flow of various signals in the / DIC mode and the control inside the DCE will be described with reference to the flowchart of FIG.

FIG. 11 illustrates the DCE to CI by issuing a CIC command from the DTE to the DCE before there is an incoming call.
The flow of various DCE-related signals when there is an incoming call in the case of the C mode is shown.

First, before an incoming call is made, the DTE at 1201
Tells that he wants to send a command to DCE by turning on the ER signal, and in 1202 DCE turns on CS / CD signal and responds to DTE. At 1203, DTE issues a CIC command to DCE and at 1204 DCE VAL indication is returned to DTE and DT is sent at 1205.
E informs that the ER signal is turned off and no other command is sent, and in 1206, the DCE responds to the DTE by turning off the CS / CD signal.

After that, if there is a ringing signal from the line at 1207, at 1208 the DCE is turned on to the DTE to notify that there is an incoming call, and at 1209 D
If an incoming call is instructed by turning on the ER signal from the TE to the DCE, the DCE is sent at 1210.
Responds to the DTE by turning on the CD signal,
Further in 1211, the DCE responds to the DTE with an INC indication. Immediately thereafter, the line is captured at 1212.

FIG. 12 shows that the DCE is DI'd by issuing a DIC command from the DTE to the DCE before there is an incoming call.
The flow of various DCE-related signals when there is an incoming call in the case of the C mode is shown.

First, before an incoming call is made, the DTE at 1301
Sends the command to DCE by turning on the ER signal, and DCE responds to this by sending CS / CD signal at 1302 and responding to DTE. At 1303, DTE issues a DIC command to DCE and at 1304 DCE sends Returns VAL indication to DTE and DT at 1305
E informs that the ER signal is turned off and other commands are not sent, and DCE responds to the DTE by turning off the CS / CD signal in 1306. After that, if there is a ringing signal from the line at 1307, DCE to DTE at 1308.
The CI signal to ON to notify that there is an incoming call, and in 1309, the DTE sends an ER signal to the DCE.
If the incoming call is instructed by setting to N, the DCE responds to this by turning on the CD signal to the DTE in 1310, and further, the DCE responds to the DTE with the INC indication in 1311. . And 131
At 2, the DCE turns on the CS signal to notify the DTE that it is in the DIC mode and that the command can be accepted. After that, at 1313, CI is transmitted from DTE to DCE.
If C command is sent, DCE responds to DTE
VAL indication is returned to 1314, and 131
Track acquisition is performed at 5.

Period 1316 from 1312 to 1313
Then, the DTE can set various modes to the DCE with commands.

Next, the operation on the DCE side will be described with reference to the flowchart in FIG.

At 1401, wait for a command from the DTE,
If a command arrives, it is checked at 1402 whether it is a DIC command. If it is a DIC command, it proceeds to 1405 and below. If it is not a DIC command, it goes to 1403 if it is a CIC command. If it is a CIC command, it proceeds to 1417 and below. Run the command
The command waits again at 1401 (because the figure becomes complicated, the movement of each signal of ER / CS / CD before the command and after the indication shown in FIGS. 11 and 12 is omitted).

1402 If the DIC command is 14
05 returned VAL indication to DTE, 14
At 06, wait for a call signal from the telephone network, and if there is this signal, the CI signal is turned on at 1407 and the DTE is turned on.
To the DTE at 1408, wait for the DTE to turn on the ER signal at 1408, turn on the CD signal at 1409 to inform the DTE, and then at 1410 to send the DTE.
The INC indication is returned to 1411, the CS signal is turned on at 1411, various commands from the DTE are waited at 1412, and if a command comes, it is judged at 1413 whether the command is a CIC command. If it is a CIC command, at 1414. The VAL indication is returned to the DTE and the line is captured at 1415. If 1413 CI
If it is not the C command, the command is executed in 1416 and then the command is waited again in 1412.

1403 If the command is a CIC command, 14
At 17, the DTE returns a VAL indication, 14
Wait for a call signal from the telephone network at 18, and if there is this signal, notify the DTE by turning on the CI signal at 1419, wait for the DTE to turn on the ER signal at 1420, and turn this signal on. If so, turn on the CD signal at 1421.
And inform the DTE, then I
The NC indication is returned and the line is immediately captured at 1415.

Relevant in the block diagram are FIGS. 1/2/3 and 4. Both connectors 107/207/307
The mode in which the DCE should operate is determined by the CIC command or DIC command sent from the DTE to the DCE through the SD signal 115/215/315 of the RAM 104/2.
04/304, and according to this mode (CIC mode or DIC mode), CPU 102/202/3
When 02 detects the call signal from the incoming call detection 105/205/305, it controls each unit according to FIG. 11/12/13.

Therefore, according to the above-described structure, there are provided two modes, that is, a mode in which the line is immediately acquired when there is an incoming call, and a mode in which the line is acquired by the CIC command after receiving the command. This allows DT when there is an incoming call.
If it is not necessary to issue various setting commands from E to DCE, it is possible to immediately shift to line acquisition, and conversely, if various setting commands need to be issued, there is a fixed period of time before command reception. Since there is no problem, various setting commands can be issued to the DCE without problem even in the DTE having a low processing capacity. In addition, the CIC /
By switching the DIC mode with a command, it is possible to flexibly respond to an incoming call.

(C) Next, regarding the configurations of FIGS. 5, 6 and 7, referring to FIGS. 8 and 9, the flow of various signals in the CIC / DIC mode, and also referring to the flowchart of FIG. The control inside the DCE will be described respectively.

FIG. 8 shows the case where the switch is set to the CIC mode, and the switch is provided in the DCE instead of the mode set in the ROM or RAM of the DCE, and otherwise. FIG. 8 of (A) above
The description is omitted here because it is the same as the description.

FIG. 9 shows the case where the switch is set to the DIC mode, and the switch is set in the DCE instead of the mode set in the ROM or RAM of the DCE, and otherwise. FIG. 9 of (A) above
The description is omitted here because it is the same as the description.

Next, the operation on the DCE side will be described with reference to the flowchart of FIG.

At 1501, waiting for a call signal from the telephone network,
If there is this signal, turn it on at 1502 and turn on the CI signal.
To notify the DTE, wait for the DTE to turn on the ER signal at 1503, and if this signal turns on, 1504
Then, turn on the CD signal to notify the DTE, then 15
In 05, the INC indication is returned to the DTE, and 15
At 06, the switch determines whether the mode is CIC / DIC mode. If it is DIC mode, at 1507, DIC becomes C
The S signal is turned on, and various commands from the DTE are waited at 1508. If a command is received, it is determined whether the command is a CIC command or not at 1509. If the command is a CIC command, VAL indication is DT at 1510.
Returning to E, the line is captured at 1511. If the command is not a CIC command in 1509, the command is executed in 1512 and then the command is waited again in 1508. Again 15
If the CIC mode is 06, the line is immediately captured at 1511.

With respect to the configurations of FIGS. 5, 6 and 7, the CPUs 402, 502 and 602 all operate according to the mode (CIC mode or DIC mode) set by the switches 418, 518 and 618.
When the call signals from 5, 505 and 605 are detected, the respective units are controlled according to FIGS. 8, 9 and 14.

Therefore, according to the above-mentioned configuration, there are provided two modes, that is, a mode in which the line is immediately acquired when an incoming call is received, and a mode in which the line is acquired by the CIC command after receiving the command. This allows DT when there is an incoming call.
If it is not necessary to issue various setting commands from E to DCE, it is possible to immediately shift to line acquisition, and conversely, if various setting commands need to be issued, there is a fixed period of time before command reception. Since there is no problem, various setting commands can be issued to the DCE without problem even in the DTE having a low processing capacity. Furthermore, in a system in which the power of the DTE is turned on for an incoming call, when switching the CIC / DIC mode by a command before there is an incoming call,
Before the power is turned off on the DCE side, the content of the mode switching command issued from the DTE, that is, which mode is set must be stored. D
There is no problem in a system in which only TE is turned off and DCE is still energized, but in a system in which DCE is also turned off, information on this mode is returned to the battery back-up.
You have to hold it up.

On the other hand, if these CIC / DIC modes can be switched by a switch, only the DCE is energized while the power of the DTE is turned off, or some circuits are backed up to the battery. There is no need to keep it.

(D) Next, regarding the configurations of FIGS. 5, 6 and 7, referring to FIGS. 8, 9, 11 and 12, the flow of various signals in the CIC / DIC mode will be described. Figure 1
The control inside the DCE will be described with reference to the flowchart of FIG.

If neither the CIC command nor the DIC command is issued to the DCE after the power is turned on and before an incoming call is made, the mode (CIC
Mode or DIC mode), the DCE operates and operates in the CIC mode if a CIC command is issued before the incoming call exists, and operates in the DIC mode if a DIC command is issued before the incoming call exists. FIG. 8 shows the flow of various signals when the switch is set to the CIC mode when operating in the mode defined by the former switch, and when operating in the mode defined by the switch as well. FIG. 9 shows the flow of various signals when the switch is set to the DIC mode.

FIG. 11 shows the flow of various signals when the CIC command is issued in the case of operating in the mode defined by the latter command. Similarly, when the DIC command is issued, various signal flows are shown. The flow is shown in FIG.

Next, the operation on the DCE side will be described with reference to the flowchart of FIG.

First, at 1601, the DCE reads the switch when the power is turned on, and if it is set to the CIC side, it is set to 1
In "602", "CIC" is recorded in a predetermined area (hereinafter referred to as "mode area") in the RAM of DCE, and if it is set in the DIC side, in 1603, DCE
Record "DIC" in the mode area of the RAM.
After that, in 1604, the command from the DTE is held, and if there is a command, in 1605 it is determined whether or not it is a CIC command. If it is a CIC command, in 1608, the VAL indication is returned to the DTE, and in 1609, the DCE R
Record "CIC" in the mode area in AM.

If it is not a CIC command in 1605, it is judged in 1606 whether it is a DIC command, and if D
If it is an IC command, 1610 returns the VAL indication to the DTE, and 1611 records "DIC" in the mode area in the DCE RAM. In the case of both the CIC command and the DIC command, when the recording in the mode area in the RAM of the DCE is completed, the command waits again at 1604 (to avoid complication of the figures, FIG. 11 and FIG. 12). The movement of each signal of ER / CS / CD before the command shown in and after the indication is omitted).

The command received from the DTE in 1606 is D
If it is not an IC command, the command is executed at 1607.

If the command does not come from the DTE at 1604, it is judged at 1612 whether there is a call signal from the telephone network, and if there is, the CI signal is turned off at 1613.
Set to N to notify the DTE, wait for the DTE to turn on the ER signal at 1614, and if this signal turns on, 161
Turn on the CD signal at 5 to notify the DTE, then 1
At 616, the INC indication is returned to the DTE and 1
According to the mode recorded in the mode area in the RAM of DCE at 617, if the DIC mode is selected, the CS signal is turned on at 1618, various commands from the DTE are waited at 1619, and if the command comes, the command is sent at 1620. Is a CIC command, and if CIC
If it is a command, 1621 will send the VAL indication.
Returning to TE, the line is captured at 1622. If 1620
If the command is not the CIC command at 1623, the command is executed at 1623 and then the command is waited again at 1619. Again 1
In the CIC mode at 617, the line is immediately acquired at 1622. If there is no call signal from the telephone network at 1612, the command is waited again at 1604.

Therefore, according to the above-described structure, there are provided two modes, that is, a mode in which the line is immediately acquired when there is an incoming call, and a mode in which the line is acquired by the CIC command after receiving the command. This allows DT when there is an incoming call.
If it is not necessary to issue various setting commands from E to DCE, it is possible to immediately shift to line acquisition, and conversely, if various setting commands need to be issued, there is a fixed period of time before command reception. Since there is no problem, various setting commands can be issued to the DCE without problem even in the DTE having a low processing capacity. Furthermore, if the CIC / DIC mode can be switched with a switch or a command, the system can be turned on by an incoming call, and the mode can be set by a switch, and it seems that the power is on before there is an incoming call. In other systems, you can switch modes with commands. Also in the former system, the power is turned on.
You can freely switch the later modes with commands.

That is, it is not necessary to energize only the DCE or to back up some circuits with the battery even while the power of the DTE is turned off. The DCE mode can be freely switched to flexibly respond to incoming calls.

(E) Next, regarding the configuration of FIGS. 1, 2, 3, and 4, with reference to FIGS. 16 and 17, the CIC
The flow of various signals in the / DIC mode and the control inside the DCE will be described with reference to the flowchart of FIG.

In this embodiment, the DCE is connected to the private branch exchange, and the ringing signal is turned on for 1 second / 2 seconds for an incoming call from the extension line and 1 for an incoming call from the outside line.
It shall be ON for 1 second / OFF for 1 second. Since the line quality is constant for incoming calls from the extension, D
TE goes into CIC mode and immediately shifts to track acquisition,
It is assumed that the DTE enters the DIC mode so that the DTE can issue various commands to the DCE in response to an incoming call from an outside line.

FIG. 16 shows the flow of various DCE-related signals when the call signal interval is ON for 1 second and OFF for 2 seconds.

If there is a ringing signal from the line at 1701,
At the start point 1702, CI from DCE to DTE
Turn on the signal, and at the end point 1703, DCE to D
The CI signal is turned off to the TE, and this is repeated for each ringing signal to notify the DTE that there is an incoming call, and the DCE itself has a length 1704 of the ringing signal ON period.
And the length 1705 of the OFF period of the ringing signal are measured, and this time is ON for a predetermined time of 1 second and OF is for 2 seconds.
Judge whether it is F or not. If so, 1706 in DTE
If an incoming call is instructed by turning on the ER signal from DCE to DCE, DCE will send D
Responding to the TE by turning on the CD signal, and further at 1708, the DCE responds to the DTE with the INC indication. Immediately thereafter, the line is captured at 1709.

FIG. 17 shows the flow of various DCE-related signals when the call signal interval is ON for 1 second and OFF for 1 second.

If there is a ringing signal from the line at 1801,
At the start time point 1802, CI from DCE to DTE
Turn on the signal, and at the end point 1803 from DCE to D
The CI signal is turned off to the TE, and this is repeated for each ringing signal to notify the DTE that there is an incoming call, and the DCE itself has a length 1804 of the ON period of the ringing signal.
And the length of the OFF period 1805 of the ringing signal are measured, and this time is ON for a predetermined period of 1 second and 1 second of OF.
Judge whether it is F or not. If so, 1806 in DTE
If the incoming call is instructed by turning on the ER signal from DCE to DCE, DCE sends D
Responding to the TE by turning on the CD signal, and further at 1808, the DCE responds to the DTE with the INC indication. Then, in 1809, the DCE turns on the CS signal to notify the DTE that it is in the DIC mode and that the command can be accepted. After that, if a CIC command is sent from the DTE to the DCE at 1810, the DCE returns a VAL indication to the DTE at 1811 and then captures the line at 1812.
Then, in the period 1813 from 1809 to 1810, D
The TE can set various modes to the DCE with commands.

Next, the operation on the DCE side will be described with reference to the flowchart in FIG.

At 1901, wait for a call signal from the telephone network,
If this signal is turned ON, the CI signal is turned ON in 1902 to notify the DTE of the incoming call and at the same time the ON period of the ringing signal is measured. If the ringing signal is turned OFF, the CI signal is turned OFF in 1903 and the ringing signal Measure the OFF period. Then, in 1904, by comparing the ON period and the OFF period of the ringing signal with a predetermined reference value, 2
Determine which of the two modes. In this embodiment, if ON for 1 second and OFF for 1 second, proceed to 1905 or less, and if ON for 1 second and OFF for 2 seconds, proceed to 1914 or less.

When the process proceeds to 1905, DT is executed at 1905.
Wait for E to turn on the ER signal, and if this signal turns on, turn on the CD signal at 1906 to notify the DTE, then return the INC indication to the DTE at 1907, turn on the CS signal at 1908. , 1909
Waits for various commands from DTE. If a command comes, 1910 determines whether the command is a CIC command. If it is a CIC command, VAL is 1911.
The indication is returned to the DTE and the line is captured at 1912. If it is not a CIC command in 1910,
After executing the command in 1913, it waits for the command again in 1909.

When the process proceeds to 1914, DT is executed at 1914.
Wait for E to turn on the ER signal, and if this signal turns on, turn on the CD signal at 1915 to notify the DTE, then return the INC indication to the DTE at 1916, and immediately capture the line at 1912. .

With the configurations shown in FIGS. 1, 2, 3 and 4, the incoming signal detection units 105, 205 and 305 detect the ringing signal, and the CPUs 102, 202 and 302 detect the ringing signal in the ON period and the OFF period. Is measured, the subsequent operation is switched to either the CIC mode or the DIC mode according to the result, and a response is made with the DTE according to the mode.

Therefore, with the above-described configuration, two or more types of processing can be separately performed depending on the difference in the time interval of the CI signal. Further, the DCE itself can automatically switch the CIC / DIC mode depending on the difference in the calling side (for example, an incoming call from an external line or an incoming call from an internal line).

(F) Next, regarding the configurations of FIGS. 1, 2, 3, and 4, the flow of various signals in two modes will be described with reference to FIGS. 19 and 20, and the flowchart of FIG. The control inside the DCE will be described with reference to FIGS.

In the present embodiment, the DCE is connected to the private branch exchange, and the ringing signal is turned on for 1 second / 2 seconds for an incoming call from an extension line and 1 for an incoming call from an outside line.
It is assumed that there are two modes, one second on and one second off. Then, the level adjustment ATT is set to 10 dB as a transmission level adjustment for an incoming call from an extension line, and is set to 5 dB for an incoming call from an outside line.

FIG. 19 shows the flow of various DCE-related signals when the call signal interval is ON for 1 second and OFF for 1 second.

If there is a ringing signal from the line in 2001,
At the start point 2002, CI from DCE to DTE
The signal is turned on, and at the end point 2003, DCE to D
The CI signal is turned off to the TE, and this is repeated for each ringing signal to notify the DTE that there is an incoming call, and the DCE itself has a length of the ringing signal ON period 2004.
And the length 2005 of the OFF period of the ringing signal are measured, and this time is ON for a predetermined period of 1 second and 1 second of OF.
Judge whether it is F or not. If so, DTE in 2006
If the incoming call is instructed by turning on the ER signal from DCE to DCE, DCE will send D
It responds to the TE by turning on the CD signal, and in 2008, the DCE responds to the DTE with the INC indication. Then, in 2009, the ATT for adjusting the transmission level inside the DCE is set to 5 dB, and immediately in 2010, line acquisition is performed.

FIG. 20 shows the flow of various DCE-related signals when the call signal interval is ON for 1 second and OFF for 2 seconds.

If there is a ringing signal from the line at 2101,
At the start time 2102, the DCE sends the CI to the DTE.
Turn on the signal, and at the end point 2103, DCE to D
The CI signal is turned off to the TE, and this is repeated for each ringing signal to notify the DTE that there is an incoming call, and the DCE itself has a length 2104 of the ringing signal ON period.
And a length 2105 of the OFF period of the ringing signal are measured, and this time is ON for a predetermined period of 1 second and then OF for 2 seconds.
Judge whether it is F or not. If so, DTE at 2106
If the incoming call is instructed by turning on the ER signal to DCE, the DCE responds to this by turning on the CD signal to DTE at 2107.
At 08, the DCE responds to the DTE with an INC indication. After this, the ATT for adjusting the transmission level inside the DCE is set to 10 dB in 2109, and then the line is captured in 2110 immediately.

Next, the operation on the DCE side will be described with reference to the flowchart in FIG.

At 2201, waiting for a call signal from the telephone network,
If this signal is turned ON, the CI signal is turned ON in 2202 to notify the DTE of the incoming call, and at the same time the ON time of the ringing signal is measured. If the ringing signal is turned OFF, the CI signal is turned OFF in 2203 and the ringing signal Measure the OFF period. Then, in 2204, the length of the ON period and the OFF period of the calling signal is compared with the reference value to determine which of the two modes. In this embodiment, 1
If it is on for 1 second and off for 1 second, proceed to 2205 or less. If it is on for 1 second and off for 2 seconds, proceed to 2210 or less.

When proceeding to 2205, DT is executed at 2205.
Waiting for E to turn on the ER signal, and if this signal turns on, turn on the CD signal at 2206 to notify the DTE, then return the INC indication to the DTE at 2207, and send the transmission level inside the DCE at 2208. The line is captured immediately after setting ATT for adjusting 5 dB to 5 dB.

When proceeding to 2210, DT is entered at 2210.
Wait for E to turn on the ER signal, and if this signal turns on, turn on the CD signal at 2211 to notify the DTE, then at 2212 return an INC indication to the DTE, and at 2213 send level inside the DCE. The line is captured immediately after setting the ATT for adjusting the signal to 10 dB.

With the configurations shown in FIGS. 1, 2, 3, and 4,
In either case, the incoming signal detection 105, 205, 305 detects a ringing signal, and the CPU 102, 202, 302 detects the ringing signal.
The lengths of the N period and the OFF period are measured, and the CPUs 102, 202, and 302 also set the ATTs 106, 206, and 306 for adjusting the transmission level inside the DCE according to the results.

Therefore, according to the above configuration, two or more types of processing can be performed separately depending on the difference in the time interval of the CI signal. Also, due to the difference in calling side (for example, an incoming call from an external line or an incoming call from an internal line), the DCE itself can automatically switch its internal setting without receiving a command from the DTE.

(G) Next, regarding the configurations of FIGS. 1, 2, 3, and 4, the flow of various signals in two modes will be described with reference to FIGS. 22 and 23, and the flowchart of FIG. The control inside the DCE will be described with reference to FIGS.

In this embodiment, the DCE is connected to the private branch exchange, and the ringing signal is transmitted for 1 second when an incoming call is received from the extension.
It is assumed that there are two modes: N / 2 seconds OFF, and 1 second ON / 1 second OFF for incoming calls from outside lines. Then, it is assumed that the DTE issues a command for setting the level adjustment ATT to 10 dB to the DCE as a transmission level adjustment for an incoming call from an extension line, and a command to similarly set to 5 dB for an incoming call from an outside line.

FIG. 22 shows the flow of various signals related to DTE and DCE when the call signal interval is ON for 1 second and OFF for 1 second.

If there is a ringing signal from the line at 2301,
At the start point 2302, the CI from the DCE to the DTE
Turn on the signal, and at the end point 2303, DCE to D
The CI signal is turned off to the TE, and this is repeated for each ringing signal to notify the DTE that there is an incoming call, and the DTE notifies the ringing signal ON period length 2304 and ringing signal OFF period length 2305. Is measured, and it is determined whether this time is ON for a predetermined period of 1 second and OFF for 1 second. If so, at 2306 the DTE is D
When the ER signal is turned on to the CE, an incoming call is instructed. At 2307, the DCE responds to the DTE by turning on the CD signal, and at 2308, the DCE INC to the DTE. Respond with an indication. Thereafter, in 2309, the DCE turns on the CS signal to notify the DTE that the command can be accepted.
At 310, the DTE is an AT for adjusting the transmission level with respect to the DCE.
Issuing a command to set T to 5 dB, D to this
The CE returns a VAL indication to the DTE at 2311 and then 23 to move the DCE to line capture.
At 12, the DTE issues a CIC command to DCE 231
At 3, the DCE returns a VAL indication to the DTE. Then, the DCE sets the ATT for adjusting the internal transmission level to 5 dB, and then immediately acquires the line at 2314.

FIG. 23 shows the flow of various signals related to DTE and DCE when the call signal interval is ON for 1 second and OFF for 2 seconds.

If there is a ringing signal from the line at 2401,
At the start time 2402, the CI from the DCE to the DTE
Turn on the signal, and at the end point 2403, DCE to D
The CI signal is turned off to the TE, and this is repeated for each ringing signal to notify the DTE that there is an incoming call. The DTE notifies the ringing signal ON period length 2404 and the ringing signal OFF period length 2405. Is measured and it is determined whether or not this time is ON for a predetermined period of 1 second and OFF for 2 seconds. If so, at 2406 the DTE is D
When the ER signal is turned on to the CE, an incoming call is instructed. At 2407, the DCE responds to the DTE by turning on the CD signal, and at 2408, the DCE makes an INC to the DTE. Respond with an indication. Thereafter, in 2409, the DCE turns on the CS signal to notify the DTE that the command can be accepted.
At 410, the DTE is an AT for adjusting the transmission level with respect to the DCE.
In order to send a command to set T to 10 dB, DCE returns VAL indication to DTE at 2411, and then 2 in order to shift DCE to line acquisition.
At 412, the DTE issues a CIC command to DCE, and 24
At 13, the DCE returns a VAL indication to the DTE. Then, the DCE sets the ATT for adjusting the internal transmission level to 10 dB, and immediately after the setting of 2414.
Track capture with.

Next, the operation on the DCE side and part of the DTE side will be described with reference to the flowchart in FIG.

The DCE waits for a ringing signal from the telephone network at 2501, and when this signal turns ON, the CI signal is turned ON at 2502 to notify the DTE of the incoming call. The DTE measures the ON period of this ringing signal, and the DCE When the ringing signal is turned off, the CI signal is turned off at 2503, and the DTE measures the length of the off period of this ringing signal. Then, the DTE determines in 2504 which of the two modes by comparing the length of the ON period and the OFF period of the ringing signal with a reference value. In this embodiment, 1 is turned on for 1 second.
If OFF for 2 seconds, proceed to 2505 or less, and if ON for 1 second and OFF for 2 seconds, proceed to 2510 or less.

When proceeding to 2505, DT is performed at 2505.
Wait for E to turn on the ER signal, and if this signal turns on, turn on the CD signal at 2506 to notify the DTE, then return the INC indication to the DTE at 2507, turn on the CS signal at 2508. , 2509
Then, the DTE issues a command to the DCE to set the ATT for adjusting the transmission level inside the DCE to 5 dB. At 2510, the DCE returns a VAL indication to the DTE to cause the DCE to acquire the line 2511.
Then, the DTE issues a CIC command to the DCE, and at 2512, the DCE returns a VAL indication to the DTE. At 2513, the ATT that adjusts the transmission level inside the DCE is set to 5 dB, and then immediately at 2514, the line is captured. To do.

When proceeding to 2515, DT is executed at 2515.
Wait for E to turn on the ER signal, and if this signal turns on, turn on the CD signal at 2516 to notify the DTE, then return the INC indication to the DTE at 2517, turn on the CS signal at 2518. , 2519
Then, the DTE issues a command to the DCE to set the ATT for adjusting the transmission level inside the DCE to 10 dB, and 2520
In response to this, the DCE returns VAL indication to the DTE and causes the DCE to capture the line 252.
In 1, DTE issues CIC command to DCE, and 2522
In response to this, the DCE returns a VAL indication to the DTE, sets the ATT for adjusting the transmission level inside the DCE to 10 dB in 2523, and then immediately captures the line in 2514.

With the configurations shown in FIGS. 1, 2, 3 and 4, the call detection signals are detected by the incoming call detections 105, 205 and 305, and these are used as CI signals 109, 209 and 309, and the DCE side connector 107, 207, 307 and DTE
The ON period and OFF of the CPU 121, 221, 321 on the DTE side through the side connectors 127, 227, 327.
The command that sets the ATT that measures the length of the period and adjusts the transmission level inside the DCE according to the result is DCE
To put out.

Therefore, with the above-described configuration, two or more types of processing can be separately performed depending on the difference in the time interval of the CI signal. In addition, the DTE is set to DC depending on the difference between the calling side (for example, an incoming call from an outside line or an incoming call from an extension line)
The type of various commands output to E can be automatically switched.

As described above, in the incoming call function switching device of the present invention, in order to solve the problems in the conventional device,
Since the line loss of the extension line is lower than that of the external line, the method of switching the transmission level is used accordingly, which enables communication with less errors and less retransmissions, in other words, communication can be completed in a short time. .

That is, as described above, the incoming call function switching device of the present invention is provided with two modes: a mode for immediately shifting to line acquisition when there is an incoming call, and a mode for shifting to line acquisition with a CIC command after receiving a command. Therefore, when it is not necessary to issue various setting commands from the DTE to the DCE when there is an incoming call, it is possible to immediately shift to line acquisition, and conversely, when it is necessary to issue various setting commands. Since there is no restriction for a certain period until the command is received, it is possible to issue various setting commands to the DCE without any problem even in the DTE having low processing capability.

[0133]

The incoming call function switching device of the present invention is based on a predetermined method of a mode of immediately shifting to line acquisition when an incoming call is received and a mode of transitioning to line acquisition by an incoming call connection command after receiving a command. Since the switching means for switching is provided, the command for various settings can be output if necessary, and the line can be immediately captured when it is not necessary to output the command for various settings. Further, a plurality of types of processing can be divided and performed according to the time interval of the CI signal. Further, the incoming call function switching device of the present invention measures and measures the time interval of turning on and off of the called table signal. Since the selection means for selecting various settings such as the transmission / reception level depending on the type of time interval is provided, two or more types of processing can be performed separately depending on the time interval of the CI signal. Also, internal settings can be automatically switched without receiving a command due to a difference in calling side.

Further, in the incoming call function switching device of the present invention, the selecting means can select the type of command to be output after that, by measuring the on / off time interval of the called table signal and the type of the time interval measured. Since it has a selection means,
Two or more types of processing can be separately performed depending on the difference in the time interval of signals. Also, the type of command received can be automatically switched depending on the difference in calling side.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of a first embodiment of an incoming call function switching device of the present invention.

FIG. 2 is a block diagram showing a configuration example of a modulation / demodulation control circuit of the incoming call function switching device of FIG.

FIG. 3 is a block diagram showing a configuration of a second embodiment of an incoming call function switching device of the present invention.

FIG. 4 is a block diagram showing the configuration of a third embodiment of the incoming call function switching device of the present invention.

FIG. 5 is a block diagram showing a configuration of a fourth embodiment of the incoming call function switching device of the present invention.

FIG. 6 is a block diagram showing the configuration of a fifth embodiment of the incoming call function switching device of the present invention.

FIG. 7 is a block diagram showing the configuration of a sixth embodiment of the incoming call function switching device of the present invention.

FIG. 8: R of DCE in the incoming call function switching device of the present invention
FIG. 9 is an explanatory diagram of the flow of various DCE-related signals when there is an incoming call when the CIC mode is set in the OM or RAM.

FIG. 9: R of DCE in the incoming call function switching device of the present invention
It is an explanatory view of the flow of various DCE-related signals when there is an incoming call when the DIC mode is set in the OM or RAM.

10 is a flow chart for explaining a control operation inside the DCE in the incoming call function switching device of FIGS. 1, 2, 3, and 4. FIG.

FIG. 11 is another explanatory diagram of the flow of various DCE-related signals when there is an incoming call when the CIC mode is set in the ROM or RAM of the DCE in the incoming call function switching device of the present invention.

FIG. 12 is another explanatory diagram of the flow of various DCE-related signals when there is an incoming call when the DIC mode is set in the ROM or RAM of the DCE in the incoming call function switching device of the present invention.

FIG. 13 is a flowchart for explaining a control operation inside the DCE in the incoming call function switching device of FIGS. 1, 2, 3, and 4.

FIG. 14 is a flowchart for explaining a control operation inside the DCE in the incoming call function switching device of FIGS. 5, 6 and 7.

FIG. 15 is a flowchart for explaining a control operation inside the DCE in the incoming call function switching device of FIGS. 5, 6 and 7.

FIG. 16 is an explanatory diagram of the flow of various DCE-related signals when there is an incoming call when the CIC mode is set in the ROM or RAM of the DCE in the incoming call function switching device of the present invention.

FIG. 17 is an explanatory diagram of the flow of various DCE-related signals when there is an incoming call when the DIC mode is set in the ROM or RAM of the DCE in the incoming call function switching device of the present invention.

FIG. 18 is a flowchart for explaining a control operation inside the DCE in the incoming call function switching device of FIGS. 1, 2, 3, and 4.

FIG. 19 is an explanatory diagram showing the flow of various DCE-related signals when there is an incoming call when the CIC mode is set in the ROM or RAM of the DCE in the incoming call function switching device of the present invention.

FIG. 20 is an explanatory diagram of the flow of various DCE-related signals when there is an incoming call when the DIC mode is set in the ROM or RAM of the DCE in the incoming call function switching device of the present invention.

FIG. 21 is a flow chart for explaining a control operation inside the DCE in the incoming call function switching device of FIGS. 1, 2, 3 and 4.

FIG. 22 is an explanatory diagram of the flow of various DCE-related signals when there is an incoming call when the CIC mode is set in the ROM or RAM of the DCE in the incoming call function switching device of the present invention.

FIG. 23 is an explanatory diagram of the flow of various DCE-related signals when there is an incoming call when the DIC mode is set in the ROM or RAM of the DCE in the incoming call function switching device of the present invention.

FIG. 24 is a flow chart for explaining a control operation inside the DCE in the incoming call function switching device of FIGS. 1, 2, 3, and 4.

FIG. 25 is an explanatory diagram of the flow of various signals between the DTE and the DCE when there is an incoming call in the conventional incoming call function switching device.

FIG. 26 is another explanatory diagram of the flow of various signals between the DTE and the DCE when there is an incoming call in the conventional incoming call function switching device.

[Explanation of symbols]

 101 data line terminating equipment (DCE) 102, 121 central processing unit (CPU) 103, 122 ROM 104, 123 RAM 105 incoming call detection section 106 level adjustment ATT 107, 127 connector 108, 128 power supply 109 modulation / demodulation control circuit section 120 data terminal apparatus (DTE) 124 input device 125 output device 126 modem NCU interface 129 switch circuit

Claims (3)

[Claims] 1. A switching means for switching between a mode in which a line is immediately transferred to a line when an incoming call is received and a mode in which a line is acquired by an incoming call connection command after receiving a command based on a predetermined method. Incoming function switching device characterized by. 2. An incoming call characterized by comprising a selection means capable of measuring a time interval of turning on and off of a called table signal and selecting various settings such as a transmission / reception level according to the kind of the measured time interval. Function switching device. 3. An incoming call characterized by comprising a selection means capable of measuring a time interval of turning on and off of a called table signal and selecting a type of a command to be subsequently output according to the kind of the measured time interval. Function switching device.