JP2766004B2 - Communications system - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a communication system that accommodates a plurality of lines and terminals and allows any terminal to respond to a hold line.

2. Description of the Related Art Conventionally, in a communication system accommodating a plurality of lines and terminals, after holding a line under communication, communication is performed on another line of the same terminal, and the terminal responds to the held call again. When responding to a held call that has been put on hold, the user changes the setting every time a call is answered in order to match the communication attribute of the held call to be answered with the communication attribute of the terminal or data adapter.

Here, the communication attributes include, for example, communication speed, stop bit, data bit length, bit format such as parity bit type, distinction between synchronous / asynchronous, character type, flow control information, voice / G3 FAX / G4 FAX / document information. And the like, such as a media type, and this information is an agreement of a communication format with a communication partner and, in some cases, a network that carries the information.

A data adapter is an adapter for a communication system such as a switching system to accommodate a data terminal device and transmit and receive data, and supports an automatic transmission / reception procedure such as V.25bis, X.21. In some cases, the communication procedure itself is not supported at all, merely to match the data terminal equipment to the modem pool in the system connected to the data terminal equipment through the interface port. Furthermore, a part that supports data communication as a part of the function of a mere stand-alone terminal device may be referred to as a data adapter.

[Problem to be Solved by the Invention] In the conventional example described above, in addition to the operation of responding to the held call by the user of the communication system, the communication attribute of the terminal or the data adapter is not matched with the communication attribute of the held call. ,
A troublesome setting operation for matching is required, and there is a disadvantage that the possibility of an operation error by the user increases, and a great deal of time and labor is required to start communication.

Also, after responding to a held call at a terminal that cannot support the requested communication attribute, the terminal performs a wasteful operation of searching for and transferring a terminal having a communication attribute capable of responding to the held call in the same communication system, or performing transfer. There is a drawback that the call cannot be made and the call is disconnected.

Furthermore, from the integration of communication services such as ISDN and the compounding of terminals, it is necessary to handle calls with various communication attributes on the same line or channel, and to deal with held calls with various communication attributes. However, there is a disadvantage that the communication system becomes inconvenient and inconvenient for the user.

[Means for Solving the Problems] The present invention has been made for the purpose of solving the above problems, and has the following configuration as one means for solving the above problems.

That is, in a communication system accommodating a plurality of lines and terminals and allowing any terminal to respond to a hold line, a call attribute storage means for storing the communication speed of the hold call, and each of the accommodated terminals responding to the respective communication speed And a setting unit for setting the communication speed of the terminal responding to the held call to match the communication speed of the held call.

Also, in a communication system that accommodates a plurality of lines and terminals and can respond to a hold line at any terminal, a call attribute storage unit that stores a bit format of a hold call, and each terminal that accommodates the call corresponds to each bit format. And a setting unit for setting the bit format of the terminal responding to the held call to match the bit format of the held call.

[Operation] In the above configuration, the user can know the communication speed or bit format of the held call, and further, the user can change the communication speed or bit format of the terminal responding to the held call to the communication speed of the held call. And the operation for matching with the bit format can be simplified, and erroneous response can be prevented.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram of a communication system which is one of preferred embodiments according to the present invention.

In FIG. 1, reference numeral 1 denotes a central processing unit (CPU) for controlling each interface, terminal device, and the entire system; 2, a memory for storing control data and setting data; and 3, a call processing program and other various controls. This is the ROM that stores the program. Reference numeral 4 denotes an exchange unit constituted by time division switches and the like, and 5 accommodates an ISDN line from an integrated digital service network (ISDN) 14 via a line termination unit (DSU) 15, and includes ISDN layers 1 and 2. , 3 protocol processing units and V.110
An ISDN interface having a speed matching unit and the like, and 6 to 8 are extension interfaces accommodating dedicated telephones and the like of the communication system.

9 is a button telephone dedicated to a communication system which is connected to an extension interface and is composed of a keypad, a speaker, a handset, a display unit and the like and handles only voice, and 10 is a built-in key telephone in addition to the voice service function of the dedicated key telephone 9. of
A data adapter telephone that can be connected to a data terminal device (DTE212) such as a personal computer through an RS-232C interface. The communication speed with DTE2 and the communication format such as bit format can be changed by an instruction from CPU1. is there. However, as described later with reference to FIG. 5, the communication speed is asynchronous from 300 bps to 9600 bps, the stop bit length is 1, 1.5, or 2 bits, and the data length is 5 to 8 bits.
The bit and parity type can be changed within a range of any combination of odd number, even number, and none. Reference numeral 11 denotes a data terminal device (DTE113) having a built-in RS-422 interface, such as a personal computer.
This is a data adapter telephone for synchronous communication (communication speed is 64Kbps).

FIG. 2 is a schematic view of a data adapter telephone used by connecting to the communication system of the present embodiment. FIG. 2 (a) shows the panel of the data adapter telephone, and FIG. 2 (b) shows an interface with the outside. Each part is shown.

In FIG. 2 (a), 21 is a main body of the data adapter telephone, 22 is a display unit for displaying character information and communication information, etc., which is constituted by an LCD or the like, 23 is a handset for voice communication, and 24 is an outside line. Is an outside line key having a call state display LED 24a. 25 is a data key for starting and ending communication, 26 is a switching key for switching communication,
27 is a dial key pad and 28 is a hold key.

The LED 24a corresponding to the outside line key 24 has the following lighting patterns depending on the state of the call.

OFF: Indicates that the corresponding outside line is empty (unused).

Fast blinking green: Indicates that the corresponding outside line is receiving a call and can respond.

Green light: Indicates that the terminal device is communicating with the corresponding external line.

Lit red: Indicates that another terminal device is in communication with the corresponding outside line, and that its own terminal device cannot communicate with the call.

Slow blinking green: Indicates that the terminal is holding the corresponding external line.

Slow blinking red: Indicates that another terminal device is holding the relevant outside line, and its own terminal device is in a state where a hold response is possible.

In FIG. 2 (b), reference numeral 29 denotes a modular jack connected to the extension interfaces 6 to 8 through a modular code, and 30 denotes an RS-232C or RS-422 interface connected to a data terminal device through a dedicated cable. Data terminal port.

The appearance of the key telephone 9 that handles voice exclusively is described in the second section.
The data terminal port 30 is deleted from the data adapter telephone shown in FIG.

FIG. 3 shows a configuration of a extension setting memory and a setting example in the communication system of the present embodiment.

FIG. 3A shows the memory configuration of the extension setting memory.
The extension ID, extension number, terminal class, and additional information for the extension include, for example, information on a communication format such as a set communication speed in the case of a data adapter telephone.

3 (b) to 3 (d) show an example of setting an extension setting memory, and FIG.
The ID is a, the extension number is 1234, and the voice class 1 is set as the terminal class. FIG. 3 (c) shows an example of the data adapter telephone 10, in which the extension ID is b, the extension number is 1235, and the terminal class is a class 2 which can handle a data terminal device having voice and RS-232C interface. The communication format (attribute) is asynchronous with a communication speed of 1200 bps, with a stop bit of 1 bit, a data bit length of 7 bits, and an even parity. FIG. 3 (d) shows a setting example of the data adapter telephone set 11. The extension ID is c, the extension number is 1236, and the terminal class is class 3 which can be connected to a data terminal device having voice and an RS-422 interface. , And the communication format (attribute) are synchronous circuit-switched terminals that are set to communicate at a speed of 64 Kbps.

These setting data can be freely set by the user according to each terminal, and can be automatically set by the CPU of the communication system. Extension numbers also correspond to ISDN subaddresses.

FIG. 4 shows a configuration of the call information holding memory in the communication system of the present embodiment and an example of the held information.

FIG. 4 (a) shows the memory structure of the call information holding memory, which is the state of the call, the extension ID and external line type of the own terminal and its number,
Then, additional information (for example, communication format or the like) for the call is held. FIG. 4 (b) shows an example of a held call, in which a party communicating via the first ISDN line is on hold by the extension having the extension terminal ID b and has an asynchronous circuit switching as a communication attribute. The communication information indicates that the communication speed is 9600 bps, the stop bit is 1 bit, the data bit length is 8 bits, and there is no parity.

FIG. 4 (c) shows an example of a call during communication, in which the extension terminal ID is b, the other party is communicating through the ISDN line 2, the communication attributes are asynchronous line switching, the communication speed is 1200 bps,
The stop bit is 1 bit, the data bit length is 7 bits, and the parity indicates that the call is an even number.

FIG. 5 shows communication attributes and classes corresponding to the communication attributes that can be tolerated by the terminals (dedicated key telephones and data adapter telephones) of the communication system in this embodiment. Class 1
Corresponds to the dedicated key telephone 9, class 2 corresponds to the data adapter telephone 10, and class 3 corresponds to the data adapter telephone 11.

FIG. 6 is a display example on the display unit of the dedicated key telephone and the data adapter telephone.

FIG. 6 (a) shows that the calling number is 123-4567, 9600 bps,
FIG. 6 (b) is an example of an incoming call display requesting asynchronous / circuit-switched data communication with a data bit length of 8 bits, no parity, and a stop bit of 1 bit. 5 is an example of display during communication in asynchronous / circuit switching in FIG. Also,
FIG. 6 (c) shows a case where the same telephone is handling two types of calls, and is an example of display when one of the calls is being communicated and the other is on hold and the call is being switched for communication.

FIG. 6 (d) is a display example in the case where the call during communication displayed in FIG. 6 (b) is put on hold, and this display state is to re-answer the held call or answer a new incoming call. And continue until communication starts. FIG. 6E is a display example when the communication attribute setting of the terminal is automatically changed.

Next, the processing procedure of the call by the CPU of the communication system according to the present embodiment will be described with reference to FIGS. 7A, 7B, 7C, and 7D.
This will be described with reference to the flowchart shown in the figure. In the following description, a terminal refers to both a dedicated button telephone and a data adapter telephone unless otherwise specified.

In step S1 of FIG. 7A, the ISDN interface 5
Based on the call setting message received from the DN network 14 via the DSU 15, it is determined whether there is an incoming call to the communication system of this embodiment. When an incoming call is detected, in step S2, the CPU 1 sets the information of the incoming call in the call information holding memory, and confirms the possibility of the communication as to whether or not there is a terminal in the communication system that is allowable in the communication attribute of the incoming call. Perform Specifically, the fifth
It is confirmed whether the incoming call can be matched with the terminal attribute classes 1 to 3 shown in the figure. For example, as a transmission capability information element (which may be a lower layer compatibility information element),
Unlimited transfer capability Digital, asynchronous 9600 bps, stop bit 1 bit, data bit length 8 bits, no parity, speed matching V.110 is specified by the calling side. Although the request is permitted, the call is not accepted if G4FAX communication is specified, despite the fact that the subaddress 1235 specifies the data adapter telephone 10.

As a result of confirming the communication possibility, if it is determined that communication is impossible because there is no terminal capable of matching the communication attribute with the incoming call, in step S3 a call is received by a release completion message accompanied by a reason display and terminal attribute mismatch. The call is rejected, the call information holding memory is released, and the process ends.

However, if it is determined in step S2 that there is a terminal capable of accepting the communication attribute of the incoming call, the process proceeds to step S4, and for the acceptable terminal, a lighting pattern (indicating that an incoming line LED is being received). (Fast blinking green), and for other unacceptable terminals, the lighting pattern during communication with other terminals (red lighting). Then, in step S5, the states of all the terminals that can be tolerated are searched, and the process branches according to the states.

For the processing for an empty terminal, refer to the steps in FIG. 7B.
In step S70, a ring tone is sounded, and in steps S71 and S72, the response of the called terminal and the termination of the incoming call due to abandonment of the calling side are monitored. If the called terminal (called terminal) responds before the incoming call stops, the process proceeds to step S75, a response message is sent to the ISDN network, and a communication path is connected in response to the incoming call.
In the next step S76, the ring tone is stopped.

Next, in step S77, the external line LED of the responding terminal is set to green light indicating that the own terminal is communicating, and the external line LED of another terminal is set to red light indicating that the other terminal is communicating. Set. However, if the incoming call is stopped before answering, the incoming call is stopped in step S73, and in step S74, the blinking or lit LED is turned off in response to the incoming call, and the terminal, interface and call are turned off. The information holding memory is released to a free state, and the process ends.

In step S78, the input of the hold key in the terminal in the communication state is monitored. If there is a key input, the process proceeds to step S79. If there is no key input, the end of the communication is monitored in step S91. In step S79, the call in communication is suspended, and the call information holding memory corresponding to the suspension is set. And
In step S80, the outside line LED of the held call is set to a slow blinking green for the terminal that has held, and a slow blinking red or lit red for the other terminals according to the communication attribute of the terminal. . Further, in step S81, the communication attributes of the held call are displayed on the holding terminal.

In step S82, input of an external line key is monitored, and step S82 is performed.
At 83, it is determined whether it is an external key corresponding to the held call. If the result of the determination is that the outside line key corresponding to the held call has been input, it is determined in step S84 whether the terminal responding to the held outside line matches the communication attribute of the held call. If they match, a connection is made between the terminal and the held call in step S89,
If not, in step S85, the communication attribute of the terminal is set to match the communication attribute of the held call.

Next, in step S86, a display indicating that the communication attribute of the terminal has changed and a tone are sounded, and in step S87, the terminal and the held call are connected. Then, in the following step S88, the display and tone stop processing executed in the previous step S86 is performed, and in step S90, the corresponding outside line LED of the hold response terminal is turned on in green, which means that the self-terminal communication is being performed, and the other is turned on. Terminal LED
Is set to light red, and the process returns to step S78 again.

On the other hand, if it is determined in step S5 in FIG. 7A that the terminal is communicating, a ringing tone is transmitted to the receiving terminal in step S13, and information on the calling side (caller number, communication speed) , Bit format, etc.) (display example of FIG. 6 (a)). Therefore, in step S14, the switching key 26
As a result of monitoring the press of the incoming line key 24 while the LED is blinking, if there is no key press, furthermore, if the stop of the incoming due to the abandonment of the calling side is monitored in step S15 and the stop of the incoming call is recognized, Then, in the next step S16, the ringing tone during the communication of the terminal is stopped, and the display is cleared. Next, in step S17, the external line LED that has been turned on in response to the incoming call is turned off, the call information holding memory is released, and the process is terminated.

If it is detected in step S14 that the incoming call external line key 24 is blinking while the LED is blinking following the switch key 26, the process proceeds to step S18.
The call currently in communication is put on hold, the information of the call is set in the call information holding memory, and the corresponding external line LED is turned on and off in green at step S19, indicating that the terminal is on hold. Then, in step S20, the communication attributes (communication formats such as communication speed, number of stop bits, data bit length, parity information, etc.) requested by the calling side and included in the call setting message at the time of incoming call are set in the called terminal. It is determined whether the communication attribute can be matched with the communication attribute by comparing the call information holding memory with the extension setting memory.

As a result of the above comparison, if they are consistent, step S21
To stop the ringing tone during communication, and clear the display section in step S22. Then, in the next step S23, a response message to the incoming call is sent to the ISDN network to complete the response to the incoming call, the communication path of the communication system is connected, and the call information holding memory is set to a communicating state.

However, if it is determined in step S20 that there is no match (for example, the current setting of the data adapter telephone 10 is 1200 bps, one stop bit, seven data bits, and even parity as shown in FIG. 3C). When set, the incoming call is specified as 9600 bps, 1 stop bit, 8 bit data bit, and no parity is specified. In step S24, the receiving terminal (in this case,
(The terminal is limited to the data adapter telephone.) The setting is automatically reconfigured according to the incoming call, and the extension setting memory is automatically rewritten. Also, in step S25, the terminal sounds a tone to notify the user that the communication format has changed, and the changed communication format is displayed on the display unit (see FIG. 6 (e)). Then, step S26
Sends a response message for the incoming call to the ISDN network to complete the response to the incoming call, and connects the communication path of the communication system. In step S27, the tone ringing in step S25 is stopped, the display is cleared, and the call information holding memory is set to a communicating state.

In FIG. 7C, in step S28, the external line LED corresponding to the communication of the communicating terminal is lit in green to indicate that the own terminal is communicating, and the corresponding LED of the other terminal is changed to another. Set to red lighting, which is the terminal communication state. In the following step S29, information (communication format) relating to the call in progress and the held call is displayed for the data adapter telephone in communication (see FIG. 6 (c)).

In steps S30 to S33, the switching key 26, the disconnection of the held call, the disconnection of the call during communication, and the disconnection of the call on the own terminal side (on-hook for voice communication, data key for data communication). Pressing will disconnect the call). If the input of the switching key 26 is detected in step S30, the process proceeds to step S34 in FIG. 7D to suspend the call during communication, sets the information in the call information holding memory, and proceeds to step S34.
In S35, the LED of the corresponding external line key is set to a state indicating that the self key is on hold, that is, the LED is slowly flashing green.

In step S36 (see FIG. 7D), the communication attribute in the call information holding memory of the call for which the switching request has been made, that is, the call that has been put on hold in step S30 (FIG. 7C), and the switching operation are performed. Check if the communication attributes in the extension setting memory of the data adapter telephone match. If the match is confirmed, the hold call with the switching request is connected in step S37, the content of the call information holding memory of the connected hold call is set to the communicating state, and the process returns to step S28 in FIG. 7C again. .

However, if it is determined in step S36D of FIG. 7D that they do not match, in step S38, the communication attribute of the terminal (data adapter telephone) that has performed the switching operation is set to the communication attribute set in the call information holding memory. Set to match,
The contents of the extension setting memory are also rewritten, and in the next step S39, a tone for informing that the communication attribute has changed is sounded, and a display indicating the communication attribute is displayed (see FIG. 6 (e)). Then, in step S40, the held call with the switching request is connected, the contents of the call information holding memory of the connected held call are changed to the communicating state, and the process proceeds to step S41 to stop the tone indicating that the communication attribute has changed. , The display is also cleared, and the process returns to S28 in FIG. 7C.

If it is detected in step S31 in FIG. 7C that the held call has been disconnected by the other party, the process proceeds to step S42 in FIG. 7D, in which the call information holding memory of the disconnected held call is released, and the LED blinking as the held call is displayed. Turn off the light. And step S
In step S43, a tone that indicates that the held call has been disconnected is sounded, in step S44, the display of the held call is cleared, and in step S45, the tone that indicates that the held call has been disconnected is stopped. The process ends.

In FIG. 7C, if disconnection by the communicating party is detected in step S32, the flow advances to step S62 to sound a tone indicating that the other party has disconnected, and step S6 is performed.
In step 3, the terminal is monitored for disconnection due to disconnection of the terminal (on-hook in the case of voice communication, pressing of the data key 25 in the case of data communication). If the disconnection of the own terminal is detected in the step S63, the step S62 is executed in a step S64.
Stop the ringing tone and clear the call display during communication. Then, in step S47, a process of releasing the call information holding memory of the disconnected call is performed.

In step S33, if disconnection by its own terminal (on-hook in the case of voice communication, input of the data key 25 in the case of data communication) is detected, in step S46 the call information holding memory of the call being communicated is released, The disconnection release processing for the outside line is performed, and in step S47, the LED corresponding to the outside line of the disconnected call is turned off. Also, in step S48, the terminal of the external line key corresponding to the call that was put on hold is set to the self-holding state (slow blinking green) as it is, and the other held calls can be tolerated. At the same time, the other devices will be put on hold (slow flashing red) for idle devices,
If the terminal is not acceptable, the terminal is in a state of communicating with another terminal (lit in red).

In step S49, an indication that there is a call on hold and information on the held call such as communication attributes are displayed, and in step S50, a tone for informing that there is a call on hold is sounded.
Then, in steps S51 and S52, the hold response (pressing the external key of the held call after the off-hook in the case of voice communication, pressing the data key 25 and the external key of the held call in the case of data communication).
When the disconnection of the call on hold is detected by the other party in step S52, the tone is stopped in step S60 and the display is cleared. Also, follow step S6
In 1, the LED of the disconnected call is turned off, the call information holding memory of the held call is released, and the process is terminated.

If a hold response is detected in step S51, step S53
In the communication attributes of the call information holding memory of the held call,
Check whether the communication attributes in the extension setting memory of the data adapter telephone that performed the hold response operation match. If the matching is confirmed in step S53, the hold call with the hold response is connected in step S54, and the corresponding external line key LED is turned on in step S59, and the data adapter telephone which is in communication is in the state of being in communication ( The other terminals are set to a state in which other terminals are communicating (lit in red), and the call information holding memory of the connected held call is set to a communicating state, and the other terminal is set to the 7B.
The process returns to step S78.

However, if it is determined in step S53 that they do not match, in step S55 the communication attributes of the data adapter telephone are set so as to match the communication attributes set in the call information holding memory, and the extension setting memory is also rewritten. Then, in step S56, a tone is sounded to indicate that the communication attribute has changed, and a tone is displayed (see FIG. 6 (e)). Also, in step S57, the call information holding memory of the held call is set to the communicating state, and the held call with the hold response request is connected.In step S58, the fact that the communication attribute has been changed in step S56 is notified. Stops the tone that is ringing and clears the display.

As described above, according to the present embodiment, a terminal connected to a communication system holds a call in communication, responds to the held call again after performing another communication with the same terminal, When answering a held call, the communication attributes of the held call and the terminal are matched at the same time as the held call is answered, so the user does not need to be aware of the consistency, and complicated operations and waste for matching are required. In this case, it is possible to avoid a troublesome call transfer operation, an erroneous response to a held call, an erroneous disconnection, and the like, thereby shortening a response time to the held call.

Also, the call information and communication attributes of the terminal stored in the communication system are displayed on the display of the terminal that performed the operation each time a hold or hold response operation is performed. In addition to matching, specific communication attributes can be visually confirmed, and there is an effect that mutual communication based on matching of communication attributes becomes more reliable.

The above embodiment is not limited to the display pattern of the LED display corresponding to the outside line key as the indication of whether or not the terminal matches the communication attribute of the held call. Multiple tones, LE corresponding to attributes
You may make it distinguishable by the color of D or a voice message.

In addition, information elements (transmission capability, lower layer compatibility, higher layer compatibility, etc.) included in ISDN messages were used as means for recognizing the communication attributes of held calls and incoming calls. A unique registration method may be adopted.

Furthermore, in the above-described embodiment, the CPU that controls the entire communication system checks and sets the consistency of the communication attribute. However, the data adapter telephone receives the control from the CPU to check the consistency of the communication attribute and perform the setting. The setting may be performed.

In the present embodiment, the communication attribute of the data adapter telephone is set to match the held call or the incoming call only when the communication attribute being set does not match the held call or the incoming call. If it is determined that the attribute of the held call or the incoming call is within the allowable range of the data adapter telephone without determining the state of the attribute, the incoming call of the held call or the incoming call is unconditionally received. It may be set to match the attribute.

[Effects of the Invention] As described above, according to the present invention, a user can know the communication speed or bit format of a held call, and further, the user can check the communication speed of a terminal that has responded to the held call. The operation for matching the bit format to the communication speed and the bit format of the held call can be simplified, and an erroneous response can be prevented.

[Brief description of the drawings]

FIG. 1 is a block diagram of a communication system according to one embodiment of the present invention, FIG. 2 (a) is an outline view of a data adapter telephone accommodated in the communication system according to the embodiment, and FIG. FIG. 3 (a) is a diagram showing a memory configuration of an extension setting memory of the communication system according to the embodiment, and FIG. 3 (b) is a diagram of an extension setting memory for the key telephone 9; FIG. 3 (c) is a diagram showing a setting example of an extension setting memory for the data adapter telephone 10; FIG. 3 (d) is a diagram showing a setting example of an extension setting memory for the data adapter telephone 11; FIG. 4 (a) is a diagram showing a memory configuration of a call information holding memory of the communication system according to the embodiment, FIG. 4 (b) is a diagram showing an example of a held call in the call information holding memory, FIG. 4 (c) ) Indicates the call information FIG. 5 is a diagram showing an example of a call in progress, FIG. 5 is a diagram showing correspondence between communication attributes and classes of terminals accommodated in the communication system according to the embodiment, and FIG. FIG. 6 (b) is a diagram showing an example of a display during communication, FIG. 6 (c) is a diagram showing an example of a display during switching communication, and FIG. FIG. 6 (d) is a diagram showing an example of a pending display, FIG. 6 (e) is a diagram showing an example of a communication attribute setting change display, and FIGS. 7A to 7D are CPUs of a communication system according to the embodiment. 3 is a flowchart showing a call processing procedure of the first embodiment. In the figure, 1 ... CPU, 2 ... Memory, 3 ... ROM, 4 ... Exchange unit, 5 ... ISDN interface, 6-8 ... Extension interface, 9 ... Key telephone, 10,11 ... … Data adapter telephones, 12,13 …… Data terminal equipment, 14 …… ISDN
Network, 15 DSU, 21 Data adapter telephone body, 22
...... Display, 23 ... Handset, 24 ... Outline key, 24
a …… Call status display LED, 25 …… Data key, 26 …… Switch key, 27 …… Dial key pad, 28 …… Hold key, 29
…… Modular, 30 …… Data terminal port.

Claims (2)

(57) [Claims] 1. A communication system that accommodates a plurality of lines and terminals and that can respond to a hold line at any terminal, a call attribute storage means for storing a communication speed of a hold call, and each of the terminals accommodates a respective communication line. First or second depending on speed
And a setting means for setting the communication speed of the terminal responding to the held call to match the communication speed of the held call. 2. A communication system in which a plurality of lines and terminals are accommodated and an arbitrary terminal can respond to a hold line, a call attribute storage means for storing a bit format of a hold call, and each of the terminals accommodates the respective bit. Control means for controlling the first or second display according to the format; and setting means for setting the bit format of the terminal responding to the held call to match the bit format of the held call. Communication system.