JPS6128252A - Transmitter possible for extension transfer - Google Patents

Abstract

PURPOSE:To attain communication between slave equipments by utilizing an auxiliary channel in incoming/outgoing frame signal in a transmitter using a 2-wire bus transmission line to attain multiplex communication between a slave device and a master device. CONSTITUTION:An auxiliary channel signal detecting and inserting circuit 14 of a slave device 2 adds a signal representing a sender, a destination and an extension transfer request to auxiliary bits S, SD and SB respectively in an auxiliary channel S of an incoming frame and transmits the result to a transmission line 4 in case of extension mutual communication. When the master device 1 detects it by an auxiliary channel signal detection and insertion circuit 15, the master set transmits a transfer permission signal formed by adding the bit SB to an idle CH designation signal to an auxiliary channel S of an outgoing frame. All slave devices 2 supervise the outgoing frame signal by the circuit 14, detects that the own device is designated by the bit SD and recognizes the sender by the bit S and the channel to be used by the bit SB. This fact is same for the sender. In this case, a signal transmission timing circuit 12 and a reception signal selection circuit 13 constitute the switching means of signal transmission and reception.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical field to which the invention pertains The present invention relates to a plurality of slave transmission devices connected to a transmission master device by a two-wire bus transmission path, and a connection between any slave transmission device and the transmission master device or an external line. The present invention relates to a transmission device that performs communication between two sub-transmission devices, and particularly relates to a transmission device that enables extension transfer and enables communication between arbitrary slave transmission devices.

Prior Art Conventionally, as shown in FIG. 5, this type of transmission device connects a plurality of slave transmission devices 21 to 2n to a two-wire bus transmission line 4, and transmits data to one end of the two-wire bus transmission line 4. Connect the target device,
It is configured by connecting the termination circuit 3 to the other end, and the transmission - 1 three units +
jIIl is connected via the public telecommunications network 5 to other similar transmission masters 1'.

Any slave transmission device 21~ connected to the main transmission device l by bus
Communication between the transmission main device 2n and the transmission main device 1 is performed by time division multiplex communication or the like. That is, the transmission main device 1 allocates an empty channel to the slave transmission device 21 with which it wants to communicate, receives the signal sent from the slave transmission device 21 to the channel, and sends the signal to another transmission master via the public telecommunications network 5. The received signal from the other main transmission device 1' is sent to the above-mentioned channel of the two-wire bus transmission line 4-F, and the signal is sent to the slave transmission device 21.
to be transmitted.

On the two-wire bus transmission line 4, there are downlink frame signals sent from the main transmission device l to the slave transmission devices 21 to 2n, and uplink frame signals sent from each of the slave transmission devices 2i to 2n to the master transmission device l. are multiplexed in a time-division or frequency-division manner and transmitted.

The conventional method described in 1-1 includes communication between each slave transmission device 21 to 2n and the main transmission device 1, and communication between the slave transmission devices 21 to 2m connected to another main transmission device 1' via the main transmission device l. However, there is a drawback that communication between extension lines cannot be performed between the slave transmission devices 21 to 2n connected to the main transmission device 1.

OBJECTS OF THE INVENTION The object of the present invention is to solve the above-mentioned conventional drawbacks and to provide an extension transfer system that enables communication between a plurality of slave transmission device groups connected to the same transmission master device via a bus. The objective is to provide a transmission device that is

Structure of the Invention In the transmission device of the present invention, a plurality of slave transmission devices are connected to one transmission main device via a two-wire bus transmission path, and the upstream frame signal and the downlink frame signal on the two-wire bus transmission path are transmitted. In a transmission device that performs multiplex communication between an arbitrary slave transmission device and a transmission main device using a direction frame signal, a slave transmission device of an arbitrary source and a slave of an extension communication partner are sent to the auxiliary channel in the up and down direction frame signals. Means for transmitting a signal etc. corresponding to each transmission device, and each slave transmission device transmitting an extension transfer request including a signal indicating a source and a signal indicating an extension destination to the auxiliary channel of an uplink frame; means for detecting a transfer permission signal sent from the main transmission device to an auxiliary channel of a downstream frame; and a means connected to the two-wire bus transmission line that always sends a signal to an upstream frame and receives a signal from a downstream frame. a 2-wire 4-wire conversion circuit for receiving data; and a switching means for switching the 2-wire 4-wire conversion circuit to send a signal to a downstream frame and receive a signal from an uplink frame as necessary; The device monitors the auxiliary channel of the uplink frame, detects an extension transfer request sent from any slave transmission device, and sends a transfer permission signal, which is a similar signal with a signal specifying an empty channel, to the auxiliary channel of the downlink frame. The present invention is characterized in that it is equipped with an auxiliary channel signal detection and insertion circuit that sends out signals to the channel, thereby enabling communication between arbitrary auxiliary transmission devices.

Embodiments of the Invention Next, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention.

That is, a plurality of slave transmission devices 2i to 2n are connected to one transmission main device l via the Type 29 bus transmission line 4, and the above two
Multiplex communication is performed between any slave transmission device and the transmission main device 1 using the upstream frame signal and the downstream frame signal on the wire bus transmission line 4, as in the conventional case. Then, as shown in FIG. 2(A), the downstream frame signal of path 4 (frame bit F, information signal channel B1
~Bk, control channel D, auxiliary channel S, etc.), the auxiliary channel S contains a signal (auxiliary bit) Si-Sn indicating a slave transmission device of an arbitrary source and a slave of an extension communication partner. Signal to indicate transmission device (auxiliary beep)
A time slot is provided in which a signal (SB1 to SBk) for specifying a communicable channel (SDi -5Dn) and a signal (SB1 to SBk) can be inserted. Further, a similar time slot is provided in the auxiliary channel S in the uplink frame signal (see (B) in the same figure).

The slave transmission devices 21 to 2n each include a transmitting circuit 9, a receiving circuit 10, a 2-wire 4-wire conversion circuit 11. Signal sending timing circuit 12. It is composed of a received signal selection circuit 13 and an auxiliary channel signal detection and insertion circuit 14. The 2-wire/4-wire conversion circuit 11 sends the transmission signal from the transmission circuit 9 to the 2-wire bus transmission path 4-1 at the timing input from the signal transmission timing circuit 12, and converts the transmission signal from the 2-wire bus transmission path 4 The reception quality is selected according to the timing from the reception signal selection circuit 13 and is supplied to the reception circuit IO. When the auxiliary channel signal detection/insertion circuit 14 wants to communicate between extensions, the auxiliary channel signal detection/insertion circuit 14 sends a signal indicating itself (sender) using the auxiliary pins (Si-Sn) of the auxiliary channel S, and sends a signal indicating the communication partner using the auxiliary bits sDi-3Dn. Sends a signal indicating the slave transmission device. For example, when the slave transmission device 2 wants to communicate with the slave transmission device 2j, it sends an extension transfer request to the auxiliary channel S with Si = ``l'' and 5Dj = ``1''. The auxiliary channel S
is 2 from the transmitting circuit 9 via the 2vj 4-wire conversion circuit 11.
In this embodiment, the auxiliary channel signal detection and insertion circuit 14 and the transmitting circuit 9 transmit a signal indicating the source to the auxiliary channel of the upstream frame on the wire bus transmission path 4. and a means for transmitting an extension transfer request including a signal indicating the destination.

The transfer request sent onto the two-wire bus transmission line 4 is input from the two-wire/four-wire conversion circuit 8 of the transmission main device 1 to the receiving circuit 7, and is detected by the auxiliary channel signal detection/insertion circuit 15. The auxiliary channel signal detection and insertion circuit 15 constantly monitors the auxiliary channel S in the uplink frame signal, and when detecting the transfer request, adds a signal specifying an empty channel to be communicated to the similar signal with auxiliary bits SB1 to SBk. For example, when channel Bh is empty, SBh = '“1”, Sj = “1”, S
A transfer permission signal with Dj = "1" is sent to the auxiliary channel S of the downlink frame.

All the slave transmission devices 21 to 2n always transmit the subsidiary channel S of the downlink frame signal to the subsidiary channel signal detection and insertion circuit 1.
4, and the slave transmission device 2j detects that it is designated as the communication destination by the auxiliary bit SDj of the auxiliary channel S of the downlink frame, and indicates that the source is the slave by the auxiliary bit Si. It identifies that it is the transmission device 2i, and also knows the channel Bh to be used by the auxiliary bit 5Bh="1''. The slave transmission device 21 similarly learns that transfer using channel Bh is permitted. In this embodiment, the receiving circuit IO and the auxiliary channel signal detection/insertion circuit 14 constitute "means for detecting the transfer permission signal sent from the transmission main device to the auxiliary channel of the downlink frame."

After that, the slave transmission device 21 transmits the channel R from the transmitting circuit 9 to the channel R.
Communication with the slave transmission device 2J is performed by transmitting the signal to be sent to h to the downstream frame on the two-wire bus transmission line 4, and receiving the channel Bh of the frame signal on the two-wire bus transmission line 4. Let's do it. This is because the signal sending timing circuit 12 of the slave transmission device 21 controls the output signal of the transmitting circuit 9 to be sent at the timing of channel Rh of the downstream frame signal, and the received signal selection circuit 13 selects the upstream frame signal. This is possible by controlling the In other words, in this embodiment, the signal sending timing circuit! 2 and the received signal selection circuit 13 constitute a "switching means for switching to send a signal to a downstream frame and receive a signal from an upstream frame".

On the other hand, the slave transmission device 2j transmits the uplink frame signal to the channel Rh and receives the signal of the downlink frame signal to the channel Bh, thereby establishing a communication line between the slave transmission devices 2j and 21. Then, by sending "1" to the auxiliary bit SBh of the auxiliary channel S of the uplink frame from the slave transmission device 2j or 21, it is reported to the transmission main device 1 that the channel Rh is in use. Also, when one communication is completed, the above auxiliary bit SBh is set to ""
Set it to 0 to indicate the end of use. Note that the slave transmission device 21
When a call is received from the public telecommunications network 5 during transfer between the extension lines of It is possible to send

FIG. 3 is a diagram showing a procedure for setting up a communication line between extensions by exchanging signals as described above.

FIG. 4(A) is a diagram showing a downward information channel signal when the slave transmission device 21 communicates with the slave transmission device of the outside line in the embodiment described in -1-, which is different from the conventional one. Similarly, one information channel is usually assigned to each slave transmission device, and the slave transmission device 21 uses channel Bi to transmit the information to the master transmission device! (B) is a diagram showing information channel signals when communication is performed between extension lines between slave transmission devices 21 and 2j connected to the same main transmission device l. Yes, the channel signal Bh from slave transmission device 2 to 2j is sent in the downstream frame, and the channel signal Bh from slave transmission device 2j to 21 is transmitted in the upstream frame, thereby forming one information channel. This shows that full-duplex extension communication is possible using .

In addition, in the two series of embodiments, the auxiliary channel S is connected to the auxiliary bits SDi -9Dn, 5i-Sn and SR1 to SBk.
Although the auxiliary channel S is configured to be divided into multiple frames and transmitted to transmit an extension request signal, a transfer permission signal, etc., it is also possible to transmit a transfer request and a transfer permission signal by making the auxiliary channel S have a multi-frame configuration, for example. In addition, auxiliary bits and
The slave transmission devices 2i to 2n of the source or destination are l:l.
It is also possible to display the transmission source, destination slave transmission device, etc. by a code signal made up of a combination of a plurality of bits without making correspondence. In this case, there is an advantage that the number of bits of the auxiliary channel S can be small.

Furthermore, the present invention is applicable to all bus connection types of communication systems, and is not limited to so-called passive buses, but is also applicable to active buses and bus terminator systems.

Effects of the Invention As described above, in the present invention, each slave transmission device sends a transfer request signal including a signal indicating the slave transmission device of the other party and itself to the transmission master device, and the transmission master device receives the above signal. A transfer permission signal with a signal specifying the channel added is sent to the bus, the slave transmission device at the other end detects the above signal, and one of the slave transmission devices sends a signal to the specified information channel of the downstream frame. 1 by switching to receive the signal of the specified information channel of the uplink frame signal.
Since the communication line is configured to be set between the originator and the destination, there is an effect that communication between extension lines is possible between any slave transmission devices connected to the bus.

By applying the present invention, a terminal 1 such as a printer on the same bus can be commonly used by a plurality of other terminals such as computers. Furthermore, if applied to home telephones, PBXs, etc., it becomes possible to communicate between extension lines, and by providing a plurality of information channels, it is possible to simultaneously communicate with outside lines, and the range of application is wide.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing an example of the configuration of uplink and downlink frame signals in the above embodiment, and FIG. FIG. 4 is a diagram showing an example of a communication line setting procedure, and in the diagram of the above embodiment, 1.1': main transmission device, 21 to 2n: slave transmission device, 3: termination circuit, 4: two-wire bus transmission road, 5: public telecommunications network, 6: transmission circuit, 7
: Receiving circuit, 8: 2-wire 4-wire conversion circuit, 9: Transmitting circuit, l
O: Receiving circuit, 11: 2-wire 4-wire conversion circuit, 12: Signal sending timing circuit, 13: Received signal selection circuit, 14: Auxiliary channel signal detection insertion circuit, ! 5: Auxiliary channel signal detection insertion circuit.

Claims (1)

[Claims] A plurality of slave transmission devices are connected to one transmission main device via a two-wire bus transmission path, and any slave transmission device is connected to the transmission device using the upstream frame signal and the downstream frame signal on the two-wire bus transmission path. In a transmission device that performs multiplex communication between a transmission main device and a transmission main device, it is possible to transmit signals, etc. corresponding to a slave transmission device of an arbitrary source and a slave transmission device of an extension communication partner, respectively, to the auxiliary channel in the up and down frame signals. and each slave transmission device sends an extension transfer request including a signal indicating a caller and a signal indicating an extension destination to the auxiliary channel of an uplink frame, and a means for transmitting an extension transfer request from the transmission master device to the auxiliary channel of a downlink frame. means for detecting the transmitted transfer permission signal; a 2-wire/4-wire conversion circuit connected to the 2-wire bus transmission line and normally transmitting a signal to the upstream frame and receiving a signal from the downstream frame; and switching means for switching the two-wire and four-wire conversion circuit to send a signal to a downstream frame and receive a signal from an upstream frame, and the transmission main device monitors an auxiliary channel of an upstream frame. an auxiliary channel signal detection and insertion circuit that detects an extension transfer request sent from any slave transmission device and sends a transfer permission signal, which is a similar signal with a signal specifying an empty channel added, to the auxiliary channel of the downlink frame. 1. A transmission device capable of internal line transfer, characterized in that communication is possible between any slave transmission devices.