Matsushita Electric Works, Ltd.

Motoharu Terada

Takashi Saeki

Yoshiharu Suzuki

Kazumasa Murakami

Osamu Akiba

Osamu Yamada

Mitsunobu Kuroda

Osamu Iijima

Satoru Suzaki

Susumu Nakano

Yuji Nakagawa

A data setting system for terminal units using an optical wireless signal includes in the respective terminal units a data storing device and a receiving device for the optical wireless signal and, in a data operating device separate from the terminal units, an operating device for preparing and transmitting a setting signal to the terminal units. The setting of data in the respective terminal units employed in a remote supervisory and controlling system using a multiplex data transmission is thereby possible from a remote position from the terminal units through the optical wireless signal.

Data setting system for terminal units in remote supervisory and

An interruption processing system in time division multiplex transmission system executes at a central control unit a group access for accessing in batch respective groups of a plurality of terminal units in response to at least part of superior bits of a specific address for one of the terminal units which requests an interruption, causes inferior bits of the address returned from the terminal unit requesting the interruption to the central unit, and allows the central control unit to specify the interruption requesting terminal unit on the basis of the superior and inferior bits of the address. Extremely rapid specification of the interruption requesting terminal unit is thereby made achievable, and the operational response time of the transmission system can be shortened to a remarkable extent.

Interruption processing system in time division multiplex transmission

An improved fire alarm system utilizes receiver and fire detecting terminals connected thereto through a signal transmission line comprising two wires. The fire detecting terminal operates on two mode, one being a contact-closure mode of transmitting to the receiver a level signal whether or not a significantly higher fire-indicative quantity is detected, and the other being intelligent mode of transmitting a digital signal indicative of the sensed quantity in the form of a superimposed signal upon the level signal in answer to the instruction from the receiver for precise and convenient analysis thereof in determining fire presence on the side of the receiver. The fire detecting terminal includes a comparator having its own threshold with which the value of the sensed analog quantity is compared for providing the level-shifted signal when the sensed analog quantity has a level higher than the threshold, notifying fire presence independently of the intelligent mode. The threshold level can be selected independently of a criterion utilized in determining first presence based upon the digital signal on the receiver, so that the above two modes can have the same sensitivity against possible fires. Accordingly, the contact-closure mode can well stand for a back-up fire detection without reduction in sensitivity.

Fire alarm system

A signal transmission system for transmitting a first signal and a second signal superposed thereupon through a common signal transmission line composed of two wires. A plurality of terminal units are connected through the common signal transmission line to a central unit and are connected in parallel with each other across the two wires of the signal transmission line. At least one of the terminal units transmits the first signal in the form of a level signal; and at least one of the terminal units transmits or receive the second signal in the form of a superposed signal on the level signal. The central unit transmits and receives the superposed signal as well as receives the level signal for receiving data or information respectively from the above terminal units. Accordingly, both the first and second signals of different types and therefore carrying different information can be transmitted between the central unit and the respective terminal units through the common signal transmission line.

Signal transmission system featuring bidirectional transmission of

In a time-division multiplex transmission system, a host machine (3) and a plurality of addressable terminals (51 to 56) are connected together by way of a signal line (6). The same address (A) is assigned to a group of the terminals (51 to 54) so that the group of terminals (51 to 54) may be placed under control at the same time upon receipt of a transmission signal (SS) from the host machine (3). Reply signals (RS1 to RS4) from the respective terminals (51 to 54) are adjusted so that they are sent back at different points in time. This enables the host machine (3) to determine which of the terminals sent back the reply signal (RS1 to RS4).

Time-division multiplex transmission system

A time division multiplex remote control system controls data transmission between a central controller and a plurality of addressable remote terminals coupled to the central controller through a signal line. The central controller transmits to each of terminals a transmission signal comprising address data addressing a terminal, control data, a reply signal standing-by period defining signal for defining a period for receiving a reply signal from the corresponding terminal, an interruption request signal standing-by period defining signal for defining a period for receiving an interruption request signal from the terminal. Each terminal receives the transmission signal and, when the received address data coincides with an address of the terminal, accepts the control data and sends a reply signal during a reply signal standing-by period. Each terminal further detects a change of a supervisory input which the terminal supervises and sends an interruption request signal at the timing of the interruption request signal standing-by period of the transmission signal.

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Kadoma, Japan

Motoharu Terada