JPH0332123Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to a local area network using signal lines of fire alarm equipment.

(Prior Art) In recent years, with the practical use of office automation, there has been an increasing need to construct local area networks for data communication between multiple terminal devices.

(Problem that the invention aims to solve) However, when constructing a local area network for mutual communication between terminals in an existing building, etc., it was necessary to lay a new communication line, and the construction work was difficult. .

Therefore, it is possible to use power lines as existing signal lines, but power lines have a lot of noise, making it difficult to use them as data communication lines.

(Means for solving the problem) The present invention was made in view of the conventional problems.In existing buildings, fire detectors installed in each room are Focusing on the fact that signal lines are installed to connect to fire alarm equipment, we developed a local area network that makes it possible to easily build a network for communication between terminal devices using the signal lines of fire alarm equipment. The purpose is to provide.

In order to achieve this purpose, the present invention uses the serial ports of multiple terminal devices to create a local area network that communicates between terminal devices. Alternatively, a first transmitting/receiving device that transmits and receives by radio such as light is installed, and a first transmitting/receiving device is installed on or near the fire detector itself connected to the signal line of the P-type fire alarm equipment located near the terminal device.
A second transmitting/receiving device is installed to communicate wirelessly with the transmitting/receiving device of the P-type fire alarm system, and a fire detector is installed between the signal lines separated for each warning area in which the second transmitting/receiving device is installed in the P-type fire alarm equipment. A filter is provided that blocks signals from the terminal devices and passes only communication signals between the terminal devices.

(Embodiment) FIG. 1 is an explanatory diagram of a network showing an embodiment of the present invention.

First, the configuration will be explained. 1 is a fire receiver in a P-type fire alarm system. A common wire L ₀ and a signal line L1 or L2 are drawn out from the fire receiver 1 for each warning area such as a floor, and the common wire L ₀ drawn out to each warning area is connected to the signal line L1 or L2, respectively. Fire detectors 10, 11, ... and 20, 2
1,... are connected. Signal lines L1 and L2 from fire receiver 1 to this fire detector and common line L ₀
A DC power supply voltage is applied between them, and when the fire detector detects a fire and operates, switching between the signal line and the common line becomes low impedance, and a fire alarm current is applied to the fire receiver 1. A fire signal is sent by passing a direct current (direct current).

On the other hand, each of 30, 31, 40, and 41 is a terminal device that performs mutual communication using a local area network, and an appropriate terminal device such as a computer terminal is used. Terminal devices 30, 3
1, 40, and 41 each have a serial port for transmitting and receiving signals with the outside, and a first transmitting/receiving device 50, 51, 6 is connected to this serial port.
0,61 are connected. First transmitting/receiving device 5
0, 51, 60, and 61 have a function of wirelessly transmitting and receiving signals from the serial port of the terminal device, for example, using radio waves, and are installed near the terminal device as shown in the figure, or are provided in the terminal device itself. .
Further, each of the fire detectors 10, 11, 20, 21 located near the terminal devices 30, 31, 40, 41 has a first transmitting/receiving device 50, 51, 60,
A second transmitting/receiving device 7 that transmits and receives signals between the terminal devices wirelessly with each of the terminal devices 61.
0, 71, 80, 81 are provided. The second transmitting/receiving devices 70, 71, 80, and 81 may be provided in the fire detector itself, or may be installed near the fire detector. Therefore, in the communication between the terminal devices 30, 31, 40, and 41, for example, if we take the mutual communication between the terminal devices 30 and 31 as an example, the output data from the serial port of the terminal device 30 is Fire detector 10 installed nearby by transmitting radio waves by transmitting/receiving device 50
The communication signal is transmitted to the second transmitting/receiving device 70 of the fire detector 11 installed near the terminal device 31 via the signal line L1 of the fire alarm equipment and the common line _L0 . from the second transmitting/receiving device 71 to the transmitting/receiving device 51 of the terminal device 31 using radio waves, and giving the received output of the first transmitting/receiving device 51 to the serial port of the terminal device 31. It becomes like this.

Next, since the signal lines L1 and L2 of the P-type fire alarm equipment are drawn out independently for each warning area, in order to enable terminal communication between the signal lines L1 and L2 of different warning areas, A filter circuit 100 is incorporated in the signal lines L1, L2 and the common line _L0 drawn into the fire receiver 1. That is, since the fire signal in the fire alarm equipment is a DC signal, the communication signal between the terminal devices transmitted via the signal lines L1 and L2 is an AC signal of, for example, several KHz to several 100 KHz, and the fire receiver 1 Filter circuit 1 installed in
00, the signal lines L1 and L2 are coupled by a filter circuit configuration consisting of a capacitor C and an inductance L, and in this filter coupling, a DC signal that is a fire signal is blocked, and only an AC signal that is a communication signal is blocked. Assume that the filter circuit has the characteristic of passing through. Of course, the input of communication AC signals to the fire reception circuit provided beyond the filter circuit 100 is also blocked.

In the case of a local area network in which terminal devices communicate with each other using signal lines in such P-type fire alarm equipment, the signal lines L1, L2 and common line L of the fire alarm equipment installed in advance are Since ₀ is used as a communication line, there is no need to install signal lines to construct a local area network, and it is possible to connect terminals by simply adding a transmitter/receiver for wireless communication to terminal equipment and fire detectors. A local area network for communication can be easily realized.

In the above embodiment, communication between the terminal device and the fire detector installed nearby was realized by a wireless method using radio wave transmission and reception, but in other embodiments, an optical communication method may be used. You may choose to adopt it.

(Effects of the invention) As explained above, according to the invention, when constructing a local area network in an existing building, the signal line of the already installed P-type fire alarm equipment can be connected to the communication line of the local area network. Because the network can be used as is, there is no need to install communication lines to construct a new local area network, since it is usually extremely difficult to install new communication lines in existing buildings, etc. By using the local area network using the signal line of the fire alarm equipment of the present invention, it is possible to easily realize a local area network for data communication between terminals, which is easy to install and inexpensive. be able to.

[Brief explanation of the drawing]

The figure is an explanatory diagram of a network showing an embodiment of the present invention. 1: Fire receiver, 10, 11, 20, 21: Fire detector, 30, 31, 40, 41: Terminal device,
50, 51, 60, 61: first transmitting/receiving device, 7
0, 71, 80, 81: second transmitting/receiving device, 10
0: Filter circuit, L1, L2: Signal line, L ₀ : Common line.

Claims (1)

[Claims for Utility Model Registration] In a local area network where serial ports of a plurality of terminal devices are used to perform data communication between terminal devices, the serial port signal is transmitted wirelessly to the terminal device itself or its vicinity. A first transmitting/receiving device for transmitting and receiving data is installed, and the first transmitting/receiving device and the first transmitting/receiving device are connected to the fire detector itself or in the vicinity thereof connected to the signal line of a P-type fire alarm equipment located near the terminal device. A second transmitting/receiving device for communication is installed, and a signal from the fire detector is installed between the signal lines of the P-type fire alarm equipment that are separated for each warning area where the second transmitting/receiving device is installed. 1. A local area network comprising a filter that blocks signals and allows communication signals between the terminal devices to pass through.