JPH0218614Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a remote monitoring device, and its purpose is to reduce the average power consumption of each terminal, and to reduce the power of the transmission signal sent from the main operation panel. The object of the present invention is to provide a remote monitoring device that can perform the following tasks.

Conventionally, as shown in FIG. 1, there is one main operation panel 1 and a large number of terminal devices ₂ each having its own unique address.
~2 _N (hereinafter abbreviated as 2) via the signal line 3, and by sequentially setting the unique address of each terminal device 2 on the main operation panel 1, each terminal device 2 is called cyclically, and the recipient In this type of remote monitoring device in which the monitoring data BD is sent back from the calling terminal 2 to the main operation panel 1, the terminal calling transmission signal V _S transmitted via the signal line 3 is rectified and smoothed and sent to the terminal. There was one in which the terminal device 2 was driven by the power of the transmission signal V _S as a power source. In such a conventional example, the monitoring input section 4 that inputs the monitoring data BD connects a series circuit of a monitoring data input contact 5 and a resistor 6 to a terminal power supply 7, as shown in FIG.
The voltage across the resistor 6 is connected to the logic circuit 9 of the terminal device 2 as the monitoring data BD.
It was supposed to be input to the monitoring input terminals K ₁ to _{K 4} of . By the way, in such a monitoring input unit 4, if any of the contacts 5 is turned on, the monitoring current I _R will always flow through the resistor 6, and the monitoring data BD will be transmitted to the terminal device 2. If it is not necessary, that is, if it is not called from the main operation panel 1 and there is no need to return the monitoring data BD, the power consumed by this current I _R is completely wasted. . Therefore, the transmission signal V _S that supplies power to the terminal power supply 7 of each terminal device 2
There was a problem in that the electric power needed to be increased more than necessary. Furthermore, if the impedance of the monitoring input section 4, that is, the resistance value of the resistor 6, is lowered to improve noise resistance, the monitoring current I _R will increase, and the above problem will become particularly noticeable.
There was a problem in that the number of terminal devices 2 had to be reduced and the signal line 3 had to be made thicker. The present invention has been made in view of the above points.

Examples will be described below using figures. FIG. 3 shows an embodiment of the present invention, in which a series circuit consisting of a monitoring data input contact 5 and a resistor 6 is connected to a terminal power source 7 through a switching element made of a transistor. is controlled by the called signal V _Y output from the terminal 2, and when the terminal 2 becomes the called terminal, the switching element 8 is turned on for a certain period of time, the monitoring current I _R flows, and the monitoring data BD are input to the monitoring input terminals K ₁ to _{K 4} of the logic circuit 9 of the terminal device 2 . In the figure, 11 is a resistor.

Figure 4 is a time chart showing the operation, and the transmission signal V _S sent from the main operation panel 1 is the start pulse signal V _P and the terminal unit 2 as shown in Figure a.
An address signal that transmits address data to call
Consisting of V _A , a control signal that transmits control data for controlling the load dependent on the terminal device 2 and returning the monitoring data BD, and V _C and a return standby signal V _W that sets the timing for returning the monitoring data BD. A return signal V _B for returning the monitoring data BD is sent out from the terminal device 2 as a current mode signal in synchronization with the return standby signal V _W as shown in FIG. On the other hand, as shown in FIG _{. d} , the called signal _V This signal goes high in synchronization with the address match signal Va (shown in c in the figure) obtained when the address matches, and the switching element 8 is turned on for a certain period of time after the address match signal Va is obtained. Ru. In the embodiment, the called signal is used to improve noise resistance.
Although V _Y is a relatively wide pulse, it goes without saying that if a latch circuit is provided in the logic circuit 9 of the terminal device 2, a narrow pulse may be used. In this embodiment, the monitoring input section 4 is activated only when the terminal device 2 requires the monitoring data BD, that is, only when the terminal device 2 is called up from the main operation panel 1. This reduces the average current consumption of each terminal 2, and no matter how the number of terminals 2 increases, two or more monitoring input units 4 of each terminal 2 can operate simultaneously. Therefore, the total monitoring current I _R is approximately equal to the monitoring current I _R flowing through the monitoring input section 4 of one terminal device 2 . Therefore, even if the resistance is lowered to increase the monitoring current I _R in order to improve noise resistance, it is possible to minimize the increase in the power of the transmission signal V _S due to the monitoring current I _R. , there is no need to reduce the number of terminals.

As described above, the present invention forms a monitoring input section by connecting a series circuit of a monitoring contact for inputting monitoring data and a resistor whose voltage at both ends is inputted to a terminal as monitoring data to a terminal power supply via a switching element. , when the terminal becomes the called terminal, the switching element is turned on for a certain period of time, and the monitoring input section operates only when the terminal is called from the main operation panel. This has the advantage of reducing the average power consumption of the terminals, reducing the power of the transmission signal sent from the main operation panel, and even when increasing the number of terminals, each monitoring input Since two or more sections do not operate simultaneously, the total monitoring current is approximately equal to the monitoring current flowing through one monitoring input section, and even if the monitoring current is increased to improve noise resistance. , the power increase of the transmission signal can be reduced,
There is an advantage that there is no need to reduce the number of terminal devices or increase the current capacity of the signal line.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing a schematic configuration of a remote monitoring device according to the present invention, Fig. 2 is a main circuit diagram of a conventional example, Fig. 3 is a main part circuit diagram of an embodiment of the present invention, and Figs. d is an explanatory diagram of the same operation. 1 is the main operation panel, 2, _{2 1} to 2 _N is the terminal, 3 is the signal line, 4 is the monitoring input section, 5 is the contact, 6 is the resistor, 7
is a terminal power supply, and 8 is a switching element.

Claims (1)

[Scope of utility model registration request] A single main operation panel is connected to multiple terminals, each with its own unique address, via a signal line, and by sequentially setting each terminal's unique address on the main operation panel, each terminal can be called cyclically. , a remote monitoring system configured to send monitoring data from the called terminal device back to the main operation panel, and to form a terminal power source by rectifying and smoothing the transmission signal for calling the terminal device transmitted via the signal line. In the device, a series circuit of a monitoring contact for inputting monitoring data and a resistor whose voltage at both ends is inputted to the terminal as monitoring data is connected to the terminal power supply via a switching element to form a monitoring input section, and the terminal A remote monitoring device characterized in that the switching element is turned on for a certain period of time when the device becomes a called terminal.