JPH0378017B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to a digital switching device using time division technology and stored programs.

[Conventional technology]

FIG. 3 is a block diagram showing a conventional digital switching device. In the figure, 101 is a switch section, 102a is a first signal transmitter, 102b is a second signal transmitter, and 103a is a first signal receiver. ,
103b is a second signal receiver, 104 is a scanner for checking the status of subscriber lines T1 to Tn, and 105 is a control unit. The control unit 105 includes a processor, and performs judgment of signals related to exchange, output of control command signals, control of operation status of exchange, etc. under storage program control. The exchange device 200 is the above-mentioned 101, 10
2a, 102b, 103a, 103b, 104,
It is composed of 104 parts. 1T, 2T,
...nT are respective terminals, T1, T2, ...Tn are respective transmission lines from the terminals to switching device 200, and R1, R2, ...Rn are respective switching devices 2
00 to each terminal.

Further, ST1 and ST2 are connected to the switch unit 1 from the first and second signal transmitters 102a and 102b, respectively.
The signal lines SR1 and SR2 leading to 01 are connected from the switch section 101 to the first and second signal receivers 10, respectively.
3a and 103b.

FIG. 4 is an operation time chart showing the passage of time of signals on each transmission line, reception line, and signal line in FIG. 3, and the same reference numerals as in FIG. 3 mean signals on the lines shown in FIG. The symbols .about.correspond to the symbols used to represent the operations at each stage in the following explanation.

Below, using FIG. 4, the operation of the device shown in FIG. 3 will be explained.
An example will be explained in which the terminal 1T communicates with the terminal 2T.

:Terminal 1T turns on transmission line T1. The switching device 200 uses the scanner 104 to constantly connect the transmission line T1.
When detecting that T1 is turned on while scanning ~Tn, the first signal transmitter 102a and the first signal receiver 103a are switched to the switch unit 10.
1 to the transmission line T1 and the reception line R1, respectively, and connect the T1 line and the SR1 line, and the R1 line and the ST
Connect one wire to each. first signal transmitter 1
02a turns on the ST1 line, so the R1 line turns on.

,: When the R1 line is turned on, the terminal 1T learns that it is allowed to dial, and sends the dial number of the terminal 2T to the T1 line.

:The first signal receiver 103a detects the dialed number, and the control unit 105 checks the dialed number and learns that the other party indicated by the dialed number is the terminal 2T.

:The second signal transmitter 102b and the R2 line, and the second signal receiver 103b and the T2 line are connected to the switch unit 10.
1, and the second signal transmitter 102b sends an on signal to notify the terminal 2T of an incoming call.

: The terminal 2T receives the signal and turns on the T2 line to notify that it will be in the receiving state.

:The second signal receiver 103b learns that the terminal 2T is in the reception state by turning on the T2 line, and notifies the control unit 105 of this.

:The control unit 105 sends an ACK (acknowledge) signal to the R1 line using the first signal transmitter 102a to notify the terminal 1T that the terminal 2T has entered the receiving state.

:The control unit 105 switches the switch unit 101 to connect the terminal 1T and the terminal 2T.

: After a switching period of the switch section 101, communication is performed between the terminals 1T and 2T.

In addition, in the above-mentioned operation example, the terminal 1T is called a calling terminal, and the terminal 2T is called a receiving terminal.

Since the conventional device operates as described above, the terminal 1T cannot immediately start data transmission even if it receives an ACK signal from the line R1, and the switch section 1
It is necessary to wait for the switching at 01 to be completed, and the time required for this switching is
Since 05 controls multiple lines T1 to Tn and R1 to Rn, the data sent from terminal 1T may be lost before the switching of switch unit 101 is completed, so the data sent from terminal 1T may be lost, as shown in FIG. The data was allowed to be transmitted to the terminal 1T after a certain period of time t.

[Problem that the invention seeks to solve]

As mentioned above, conventional devices have the problem of having to wait a certain period of time after receiving an ACK signal before transmitting data.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a switching device that allows a terminal to immediately start data transmission when the terminal is notified of an ACK signal.

[Means for solving problems]

In this invention, by providing a delay circuit between the transmission line and the switch section as seen from the terminal side,
Even if the terminal starts data transmission immediately when the ACK signal is notified to the terminal, the switching at the switch section is completed by the time the data reaches the switch section.

[Effect]

When the terminal is notified of the ACK signal, the terminal can immediately start data transmission, eliminating waiting time.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention, in which the same symbols as in FIG. 3 indicate the same or corresponding parts, 1D, 2D, . . . nD are delay circuits, I1, I2, . In switches the output of each delay circuit 1D, 2D, ...nD to the switch section 101.
This is the signal line leading to.

FIG. 2 is an operation time chart showing the passage of time of signals on each transmission line, reception line, and signal line in FIG. 1, and is displayed in the same format as FIG. 4.

The operation of the apparatus of the present invention will be explained below with reference to FIGS. 1 and 2. As is clear from a comparison between FIGS.
, , , are the same in the apparatus shown in FIG. 1 as in the apparatus shown in FIG. 3, so a redundant explanation of the operations in these parts will be omitted.

In FIG. 2, the portions marked with are the operational steps specific to the apparatus of the present invention, which will be explained below.

:The terminal 1T starts data transmission immediately upon receiving the ACK signal.

:The data whose transmission is started in the operation stage is delayed by 1D by the delay circuit and becomes a signal on the I1 line and enters the switch section 1. Since the switching of the switch unit 1 is completed during the delay time by the delay circuit 1D, the signal on the I1 line is output onto the R2 line and reaches the destination terminal 2T.

The delay circuits 1D, 2D, . . . nD may have any configuration. For example, it may be a delay circuit using a shift register, or it may be a first-in-first-out (FIFO) memory where information is held within the circuit until it is read out. good. In the case of a FIFO memory, data arriving at the switch section 1 can be held until the switching operation of the switch section 1 is completed.

〔Effect of the invention〕

As described above, according to the present invention, a delay circuit is inserted into the transmission line from the terminal to the switch section, so that the terminal starts transmitting data immediately upon receiving a signal indicating completion of call connection or an incoming call instruction signal. I can do it.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is an operation time chart showing the time course of signals on each transmission line, reception line, and signal line in FIG. 1.
FIG. 3 is a block diagram showing a conventional device, and FIG. 4 is an operation time chart showing the passage of time of signals on each transmission line, reception line, and signal line in FIG. In the figure, 1T, 2T, ... nT are terminals, 1D, 2D, ... nD are delay circuits, respectively.
101 is a switch section, 102a is a first signal transmitter, 102b is a second signal transmitter, 103a is a first signal receiver, 103b is a second signal receiver,
104 is a scanner, 105 is a control unit, and 200 is an exchange device. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Claims] 1. Each transmission line from each of the plurality of terminals, each reception line from each of the terminals, first and second signal transmitters that transmit connection control signals, and receive connection control signals. a first and second signal receiver, each of the transmission lines, each of the reception lines, the first and second signal transmitters, and a switch unit that switches connections between the first and second signal receivers; In a switching device having a scanner that scans the signal state on each of the transmission lines, and a control unit that centrally controls the switching control operation, each delay circuit that delays the output of each of the transmission lines and inputs it to the switch unit; A transmitting line from a transmitting terminal whose transmitting line is detected to be in an ON state by a device is connected to the first signal receiver, and a receiving line from the transmitting terminal is connected to the first signal transmitter. means for detecting a dial number sent from the calling terminal, which detects the called terminal from the dial number, connects a transmission line from the called terminal to the second signal receiver, and connects a receiving line from the called terminal to the second signal receiver; means for notifying the receiving terminal of an incoming call by connecting to a second signal transmitter, and notifying the calling terminal by means of the first signal transmitter that the receiving terminal is in a receiving state; means for connecting the above-mentioned calling terminal and the receiving terminal via the switch section, and data sent by the calling terminal that has been informed that the receiving terminal is in a receiving state is connected via the switch section between the sending terminal and the receiving terminal. 1. An exchange device comprising: means for setting the delay circuit so that the signal is input to the switch section after the signal has been switched. 2 Delay circuit as first-in first-out memory (FIFO memory)
An exchange device according to claim 1, characterized in that it is constructed by: