JPS594253A - Terminal device of contact input - Google Patents

Abstract

PURPOSE:To provide flexibility to a transmission system connecting terminals, by constituting a device of contact input terminal device itself generating a synchronizing signal. CONSTITUTION:Delay time tau0-taun of optical delay circuits 3, (3-1)-(3-n) of the contact input terminal device 10 have the relation of tau0<tau1, tau2...taun. An optical signal entering the delay circuit 3 is outputted at first to an optical output terminal without being disconnected, and the optical pulse signal entering the other delay circuit is outputted with the optical switch being turned on only. That is, first one optical pulse is outputted without fail after the delay time tau0, and then the optical pulse train in response to the on/off state of each optical switch is outputted. Thus, in taking synchronism with the pulse outputted at first among optical outputs, the correspondence between the succeeding pulse train and each switch is taken easily. In this case, since the terminal itself outputs the synchronizing signal at first, even if the distance between the contact information collecting terminal and the optical contact input terminal is changed, it is not required to acquire the synchronism again at all.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an input terminal device for inputting contact information to a transmission system in an optical information transmission system that collects information on a plurality of contact points.

A conventional device of this type was constructed as shown in FIG.

That is, the optical pulse signal A input from the optical input terminal +11
passes through the optical branch (2) to each optical delay circuit (3-1)S(3-
n), enters the optical contact (4-1) −= (4-n) after a delay of each individual delay time τ1Sτn, and only the ON signal of the optical contact further passes through the optical convergence path (5). It is output to the optical output terminal (6). The on/off state of the corresponding optical contact can be determined by the presence or absence of a pulse at a certain time in the optical output from the optical output terminal (6).

However, with this conventional device, it is not possible to obtain a synchronization signal for making correspondence between the optical pulse train outputted to the optical output terminal and each optical switch.
As shown in the figure.

An optical transmitter Qυ and an optical receiver (
In the same way as (c), it was necessary to achieve synchronization using a synchronization signal generator (c). Not only is this complicated, but also 1. For example, if the distance between the contact information collection terminal and the contact input terminal +1% changes, the delay time of the optical signal that occurs between them changes accordingly. ○This invention aims to eliminate these drawbacks.

The contact input terminal device itself outputs a synchronization signal, and the following nine drawings will be explained in detail. is light branching, (3) and (3-1), -(
3-n) Fi optical delay circuit, (4-1) -(4-n
) is an optical switch, (5) is an optical combining circuit, and (6) is an optical output terminal.

Also, optical delay circuits (3) and (3-1) −= (3-n
) give a delay time of τOHτn to the optical signal, but
The following relationship is established between each delay time.

τ0〈τ1. τ2 , °°−τn −−−Le−−
------------(11) Now, the optical pulse input from the optical input terminal is branched at the optical branch and becomes a signal delayed by a certain time θ in each delay circuit. ) is not cut off and is outputted to the optical output terminal earlier than the signal input to any other delay circuit due to the relationship in equation (11). ) H(3
-n), the optical switch after this is turned OFF.
Only N items are output to the optical output terminal.

That is, in this optical contact input terminal, when an optical pulse signal is input, one optical pulse signal is always output after a specific delay time τ0, and following this optical pulse signal, each optical switch is turned on.

A light pulse train corresponding to the off state is output.

Therefore, when using this contact input terminal device, if synchronization is achieved using the pulse signal that is first output after optical input, it is possible to easily match subsequent pulse trains to each switch. In such a 9-lever contact input terminal device, the terminal itself first outputs a synchronization signal.

As seen in the conventional device shown in FIG.

No matter how the distance between the contact information collection terminal and the optical contact input terminal changes, there is no need to adjust the synchronization at all, and there is an advantage that the configuration of the transmission system is flexible. In addition, since the first pulse signal for synchronization is never disconnected, the presence or absence of this synchronization pulse signal may also occur, for example, in the event of an accidental disconnection of the transmission line between the contact input terminal device and the information collection terminal. It also has the advantage of being more detectable.

FIG. 4 shows another embodiment of this invention,
(1) is an optical input terminal, (2) is an optical branch, and (3) is a group of optical delay circuits for obtaining a synchronization signal.
It consists of two delay circuits.

It's working.

τ01〈τ1. τ2. ”'τn, -----------
−−−−1−−−−(21τ02〈τ1.τ2+ ”°
τn, −−−−−−−−−−−−−−−−−−+3)
Further, τo1 and τo2 are selected as follows.

τo1−τ02 = t −−−−−−−−−−−−
---------1---(41 Here, t is the pulse width of the optical pulse to be input to this terminal. Also, τ02.
τ1−τ. The difference between any two delay times is chosen to be greater than one in the optical pulse. The operation of this terminal is as follows. An optical pulse signal having a pulse width t inputted from an optical input terminal (1) is branched by an optical branch, and a portion enters an optical delay circuit group (3). Optical delay circuit group (3) Since the delay time of the two delay circuits that make up the entire configuration satisfies equation (4), the pulse width of the optical signal output to the optical delay circuit group +311 and optically combined is exactly the pulse width of the human pulse. It is converted into a pulse signal with twice the pulse width.

Now, it is branched by the optical branch (2) and connected to another delay circuit (3).
-1) -= The optical signals input to (3-n) are each subjected to a predetermined delay time τ1-τn, and the optical signals input to the optical switch (4-9
is also large, so the pulse train output from the optical output terminal is
All pulses have a pulse width t, except for the pulse that has passed through the optical delay circuit group (3) for obtaining a synchronization signal, which has a pulse width 2t i. Also, since Equation 1+21 and (31 hold true, the pulse with a pulse width of 2t for this synchronization is located at the beginning of the pulse train. Therefore, if synchronization is achieved with an output pulse whose width is twice that of the input pulse, the subsequent The correspondence between the pulse train and each switch can be easily established.

In this embodiment, unlike other pulse signals, the synchronization pulse signal has a clear feature of having twice the pulse width, so when the optical pulse is sent to the contact input terminal device as in the first embodiment described above, It has the advantage that synchronization is possible by detecting only the optical output without the need for any information as to whether the optical signal has been input.

As described above, in the contact input terminal device according to the present invention, since the terminal itself is configured to generate a synchronization signal,
This has the advantage of being able to provide flexibility to the transmission system that connects the terminals.A block diagram showing one embodiment of the input terminal device, FIG. 4 shows another embodiment of the optical contact input terminal device according to the present invention. It is a block diagram.

In the figure, (1) is an optical input terminal, (2) is an optical branch, (3) and (3-1) to (3-n) are delay circuits, and (4-1) to (
4-n) is an optical switch, +51i optical combining circuit, and (6) is an optical output terminal.

(II Fi contact input terminal device. In Figure 1, the same 6 or corresponding parts are indicated by the same reference numerals.

Patent applicant: Director of the Agency of Industrial Science and Technology Makoto Ishiita

Claims (1)

[Claims] In a contact input terminal device comprising an optical input/output terminal, a plurality of optical contacts connected between the input/output terminals, and a plurality of optical delay circuits connected to each optical contact, the plurality of optical delay circuits are provided. 1. A contact input terminal device characterized in that at least one other optical transmission line having a delay time shorter than that of any other optical transmission line is formed between optical input and output terminals.