JPH01251999A - Data transmission system - Google Patents

Abstract

PURPOSE:To set either a transmission mode or a reception mode with a simple system in short transmission time by sending a synchronization pulse longer than an ordinary signal pulse from a main console plate and setting either the transmission mode or the reception mode, for example, by making time from the fall of the synchronization pulse to the rise of the next signal different. CONSTITUTION:When the mode of a main console plate 1 is to be made into the transmission mode, as shown in a signal (a), the transmission mode is set by queuing for prescribed time t1 after the synchronization pulse is sent. On the other hand, when the mode of the main console plate 1 is to be made into the reception mode, the mode of the main console plate 1 is made into the reception mode by sending an appropriate signal by the main console plate 1 after prescribed time (the time shorter than t1) t2 passes after the synchronization pulse is sent as shown in a signal (b). Since the transmission mode and the reception mode are set separately in the time, for example, from the fall of the synchronization pulse to the rise of the next signal in this manner, a special mode signal is unnecessary, and either the transmission mode or the reception mode can be easily set in the time approximately equal to the time for 1 bit of the signal.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a data transmission system, and particularly relates to a main operation panel, a terminal device connected to the main operation panel via a transmission line, and a data transmission system connected to the terminal device. The present invention relates to a data transmission method that is suitable for application to lighting control systems and the like that include lighting equipment that can be controlled by signals sent from terminals.

[Prior Art] FIG. 1 shows a schematic configuration diagram of a lighting control system which is a conventional example and is also an example to which the present invention is applied. The system shown in the figure includes a main operation panel 1, a terminal device 3 connected to the main operation panel 1 via a transmission line 2, and a lighting load 4 that is turned on at a predetermined illuminance in response to data transmitted from the terminal device 3. It is equipped with

Conventionally, in a data transmission system applied to this type of lighting control system, etc., a dummy signal was usually transmitted in a predetermined format along with a mode signal indicating a reception mode or a transmission mode.

FIG. 3 shows the format of a conventional transmission signal. 1st
When the main operation panel 1 shown in the figure wants to set the transmission mode, a value indicating the transmission mode is set in the mode position in the format shown in Figure 3, and if necessary, the address and control information parts are dummy signals. is sent from the main operation panel 1. After receiving the return signal from the terminal device 3, the main operation panel 1 becomes in the transmission mode and becomes capable of data transmission. To set the reception mode, set a value indicating the reception mode in the mode position in the format shown in FIG. 3, and do the rest in the same way as setting the transmission mode.

[Problems to be Solved by the Invention] By the way, according to such a conventional example, it is necessary to send out a mode signal of about 4 bits in order to set the transmission mode or reception mode, and if necessary, a dummy signal is also sent. It was necessary to use this signal. Therefore, there is a problem that the signal becomes complicated and takes time.

In view of the problems of the prior art described above, it is an object of the present invention to provide data that allows setting of a transmission or reception mode in a simple manner and in a short transmission time without requiring a special mode signal indicating the transmission mode or reception mode. The goal is to provide a transmission method.

[Means and effects for solving the problem] In order to achieve the above object, the present invention transmits a synchronization signal, an address signal, and a control signal from a main operation panel, and determines the transmitted signals by a terminal device to detect a load. A data transmission method used in systems that control systems, in which the synchronization pulse for synchronization is longer than the signal pulse, and the time from the change in the synchronization pulse to the next change in the signal is different depending on the transmission mode or reception mode. It is characterized in that the transmission mode or reception mode is set by this.

According to the above configuration, a synchronization pulse that is longer than a normal signal pulse is sent from the main operation panel, etc., and the time from the fall of the synchronization pulse to the rise of the next signal is varied to set the transmission mode or reception mode. can be done.

[Example] Hereinafter, the present invention will be explained in detail using the drawings.

In this embodiment, the present invention is applied to a lighting control system having the configuration shown in FIG.

FIG. 2 is a waveform diagram showing the transmission mode setting signal a and the reception mode setting signal S in this embodiment.

When the main operation panel 1 wants to enter the transmission mode, it waits for a predetermined time t1 after sending out the synchronization pulse, as shown by signal a. As a result, the transmission mode is set. on the other hand,
When the reception mode is desired, the main operation panel 1 sends out an appropriate signal after a predetermined time (time shorter than tl) t2 after the synchronization pulse, as shown in the signal diagram. This causes the main operation panel 1 to enter the reception mode.

Note that generating and recognizing synchronization pulses that are longer than normal signal pulses and determining the time from one synchronization pulse to the next can be achieved with a simple configuration. .

[Effects of the Invention] As explained above, according to the present invention, the transmission mode and reception mode are set by distinguishing, for example, the time from the falling edge of a synchronizing pulse to the rising edge of the next signal. The transmission mode or reception mode can be easily set in a time period corresponding to one bit of the signal without requiring a detailed mode signal.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a lighting control system, which is a conventional example and an example to which the present invention is applied. FIG. The waveform diagram in FIG. 3 is a diagram showing the format of a conventional mode setting signal. 1... Main operation panel, 2... Transmission line, 3... Terminal, 4... Lighting load.

Claims (1)

[Claims] 1. A data transmission method used in a system in which a synchronization signal, an address signal, and a control signal are sent from a main operation panel, and a terminal device discriminates the transmitted signals to control a load, the data transmission method comprising: The synchronization pulse for the signal is set longer than the signal pulse, and the time from the change in the synchronization pulse to the change in the next signal is made different depending on the transmission mode or reception mode, thereby making it possible to set the transmission mode or reception mode. Characteristic data transmission method.