JPH0326959B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a digital operator trunk circuit used in an office collective central office device of a digital telephone switching system.

(Prior art) Conventionally, as a technology in this field, there is a D10 type automatic switch office collective telephone office equipment described in the document ``D10 type automatic switchboard [Hardware]'' published by the Telecommunications Mutual Aid Society, edited by Nippon Telegraph and Telephone Public Corporation. The operator trunks used in this system are two-wire analog trunks, but with the digitization of telephone exchanges, the operator trunks must also be digitized.

When configuring a digital operator trunk circuit,
A three-way communication circuit can be easily realized using digital signal processing technology, which is a well-known technology, as described in a document published by Nippon Telegraph and Telephone Public Corporation, February 1, 1982, for example, D70 type automatic switch hardware. Although this is possible, it is necessary to realize a circuit that can arbitrarily control the states of external calls, internal calls, and monitoring calls.

(Problems to be Solved by the Invention) In this case, if the circuit configuration is such that a state control circuit is simply added to the three-way communication circuit, the state control timing will be complicated and the circuit configuration will also be complicated. It was hot.

(Means and effects for solving the problem) The present invention has been made to solve the above-mentioned drawbacks, and it adds a simple selection circuit to the three-party communication circuit and selects the three-party communication circuit at the same timing as the input time slot. The circuit configuration is such that the selection circuit is controlled by inputting a state control signal.

Embodiments of the present invention will be described in detail below with reference to the drawings.

(Embodiment) FIG. 1 shows an embodiment of the present invention, in which 1 is an operator input terminal, 2 is an extension input terminal, 3 is an outside line input terminal, and 4 is a state control signal input terminal. As shown in the figure, each input terminal is connected to a three-way communication circuit 5 and a selection circuit 6 provided for each input terminal, and the output of each selection circuit is connected to an operator output terminal 7,
It is connected to an output terminal 8 for an extension line and an output terminal 9 for an outside line.

The three-party communication circuit 5 is a well-known technology and will not be described further. Reference numeral 10 denotes a fixed delay circuit for adjusting timing between three-party calls and other calls.

FIG. 2 is a state control signal pattern diagram for controlling the call state of the operator's trunk, and is input to the state control signal input terminal 4 at the same timing as each time slot input to terminals 1-3.

As shown in FIG. 3, the time slots input to each terminal 1 to 3, such as AO, BO, and CO, correspond to the corresponding three-way communication circuit 5 and selection circuit 6.
is input to each time slot, but is selected by the selection circuit 6 according to the state control signal PO input at the same time as each time slot, and is output to a predetermined output terminal. For example, if the status control signal PO is a pattern 2 external call,
The selection circuit 6 selects the input 2.

In other words, AO is output to the outside line terminal, CO is output to the operator terminal, and the no-call pattern is output to the extension terminal.
NT is output.

With such a circuit configuration, a simple and straightforward digital operator trunk can be realized.

(Effects of the Invention) As explained above, according to the present invention, a simple selection circuit is provided, a control signal is input at the same timing as the input time slot, and the selection circuit is used to perform three-way calls and
By directly selecting and outputting one of the input signals of the selection circuit according to the state control signal that controls the four states of external line calls, internal calls, and supervisory calls, no memory or control circuit is required, and the circuit configuration is simplified. It becomes simple.

Therefore, not only is the economical efficiency of the individual operator trunk circuit improved, but also a plurality of operator trunk circuits can be installed as required, which has the advantage of increasing the economical effect of the system as a whole.

[Brief explanation of the drawing]

FIG. 1 is a block configuration diagram showing an embodiment of the present invention, FIG. 2 is an example of the state control signal pattern of FIG. 1,
FIG. 3 shows an explanatory diagram of the operation of FIG. 1. 1...Input terminal for operator, 2...Input terminal for extension line, 3...Input terminal for outside line, 4...Status control signal input terminal, 5...Three-party communication circuit, 6...Selection circuit, 7... ...output terminal for operator, 8...output terminal for internal line, 9...output terminal for outside line.

Claims (1)

[Claims] 1. A digital operator used in a telephone device of a digital telephone exchange system, which has three types of input and output terminals for operator calls, outside line calls, and extension calls, and a status control signal input terminal. In the trunk, there is a three-way communication circuit that can add the signals of the input terminals, and the output side is connected to the respective output terminals for the operator, outside line, and extension, and the input side is connected to the other input terminals other than the own input terminal for three-way communication. Connect the circuit's own terminal output to the input side, and use the state control signal to select one from multiple input signals.
A selection circuit that selects and outputs one is provided, and the time slot and status control signal input from the operator, outside line, and extension input terminals are input at the same timing, and three-way calls and outside line calls are made. - An operator trunk circuit characterized in that digital multiplex processing is performed by selecting and outputting one of the input signals of the selection circuit in accordance with a state control signal that controls four states of an extension call and a supervisory call.