JPS62171241A - Time division multiplex communication system - Google Patents

Abstract

PURPOSE:To decrease the number of operating channels of time division multi plex communication from 2 channels into one channel while keeping the reliabil ity of a duplicated communication line by adding a different address for each interface adaptor identification to a sending packet and using its identification address so as to discriminate each communication. CONSTITUTION:A packet sending circuit 1 in an equipment ST adds an identification address 1 to a data, when it comes from one communication line L1 and a time division multiplex TDM frame is sent to a time slot of a channel 1. When a data comes from other communication line L2, the packet transmission circuit 1 adds an identification address 2 to shape the packet form and the TDM frame is sent in the time slot of the channel 1. Thus, since which of the duplicated communication lines L1, L2 is to be used depends of the identification address added to the TDM frame, the number of operation channels is decreased from 2 to 1 channel.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a time division multiplex communication method in a communication system that performs time division multiplex communication between a plurality of communication devices connected via a duplex communication line. Regarding. More specifically, the present invention relates to an improvement in a channel (time slot) control method in a communication system where a duplex communication line is not used simultaneously in time series, such as when one side is on standby or both sides are used alternately. It is.

(Prior Art) FIG. 4 is a configuration explanatory diagram showing a communication line coupling section in a time division multiplex communication system. In the figure, Ll.

L2 is a duplex communication line, and ST is a time division multiplex communication device, which includes an interface adapter that interfaces with the duplex communication line, and provides two channels (time slots) for the duplex communication lines Ll and L2. Assigned.

FIG. 5 is an explanatory diagram of the operation of duplex communication in this communication system. Figure 5(a) shows that during normal operation, one communication line L1 is used, and the other communication line L2 is in a standby state, and when an accident occurs, it remains in a standby state until then. This method uses the other communication line L2. FIG. 5(b) shows communication lines L1 and L2.
In this system, both communication lines L1 and L2 are used alternately, and both communication lines L1 and L2 are checked at all times, and when an accident occurs, the normal communication line is used.

(Problems to be Solved by the Invention) In such a conventional communication system, there was a problem in that two channels were occupied by the interface adapter of each communication device, resulting in poor communication efficiency.

The present invention was made in view of these problems, and
The purpose is to provide a communication system that can reduce the number of channels used for time division multiplex communication from two channels to one channel while maintaining the reliability of duplex communication lines.

(Means for Solving the Problems) The configuration of the present invention that achieves the above-mentioned object is advantageous in a communication system that performs time division multiplex communication between a plurality of communication devices connected via a duplex communication line. The interface adapters that connect each communication device and the redundant communication line correspond to each line, have the same communication channel, and send out different addresses to identify each interface adapter. ) K is added, and each communication is discriminated based on the identification address.

(Embodiment) FIG. 1 is a diagram showing the configuration of a device to which the communication method of the present invention is applied. In the figure, 1 is a packet transmission circuit;
An identification address is added to the transmission data (TX DATA), the transmission packet format is adjusted, and the packet is sent to the transmission data (TX DATA).
PACKET). 2 is an address discrimination circuit, which is given the identification address of its own station, and which recognizes the received packet y.
) (RX PACKET) is addressed to the local station (2) based on the identification address. 3 is receiving bucket 2
) (RX PACKET), inputs the detection signal DET indicating that the packet is addressed to the local station from the address discrimination circuit 2, separates the identification address from the data, and reads the data (RXDATA). Incorporate.

FIG. 2 is a conceptual diagram illustrating the connection to the duplexed communication lines L1 and L2.

This configuration is the same as that shown in FIG. 4 in that two channels are assigned to each communication line LL, 1, 2, but each channel has an identification address JI, J.
They differ in that I is set respectively.

The operation of the apparatus configured as described above will now be described with reference to the time chart of FIG.

In FIG. 2, the packet transmission circuit 1 in the device ST is
@3 As shown in Figure (A), when data arrives from one communication line Ll, an identification address ('1') is added to it as shown in (C), the packet format is adjusted, and the data is sent to channel 1. time division multiplexing (TDM)
Sends 7 frames. When the packet receiving circuit 3 receives a packet sent from the time slot of channel 1 in another device, the address discriminating circuit 2 determines the identification address added to the packet,
If it is addressed to t (=1), the data is taken in. The captured data is sent out through one communication line L1'K, as shown in FIG. 3).

Next K, as shown in Figure 3 (b), the other communication line L
When data arrives from 2, the packet transmitting circuit 1 transmits (
Add an identification address (lz#) as shown in c),
The packet format is adjusted and the TDM frame is sent to the time slot of channel 1. If the received packet on channel 1 in another device is addressed to the device itself (=2), the packet receiving circuit 3 takes in the data and sends it to the communication line L2' as shown in FIG. 3 (e). Send this data.

As described above, an identification address is added to the TDM frame to determine which of the duplexed communication lines LL and L2 is to be used, and this is done according to this identification address. This reduces the number of channels and simplifies the control of channel access.

(Effects of the Invention) As described above, according to the present invention, the number of channels used for time division multiplex communication can be reduced from two channels to one channel while maintaining the reliability of the duplex communication line.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the configuration of a device to which the communication method of the present invention is applied, FIG. FIG. 4 is a configuration explanatory diagram showing a conventional communication line coupling section in a time division multiplex communication system, and FIG. 5 is an operational waveform diagram thereof. LL, L2... Duplex communication line, 1... Packet transmitting circuit, 2... Address discrimination circuit, 3... Bucket receiving circuit. Agent: Patent Attorney Makoto Ozawa, Suke ＼、（、、）、ノ′

Claims (1)

[Claims] In a communication system that performs time-division multiplex communication between a plurality of communication devices connected via a duplex communication line, an interface adapter that connects each communication device and the duplex communication line corresponds to each line, A time division multiplex communication system characterized by using the same communication channel, adding different addresses to outgoing packets to identify each interface adapter, and discriminating each communication based on the identification address.