Network system

network system {Network system}

1 is a block diagram showing the configuration of a network system in which two products are connected using one communication line according to the prior art;

2 is a block diagram showing the configuration of a network system in which two products are connected using one communication line according to the present invention;

3 is a circuit diagram showing the detailed configuration of the adapter of FIG.

4 and 5 are impedance equivalent circuit diagrams of FIG. 2

Explanation of symbols for main parts of the drawings

40: PC 50, 60: Product

70: adapter Q1, Q2: transistor

<background-art><p>The present invention relates to a network system for remote control and monitoring of home appliances.</p><p>In general, when remotely controlling or monitoring home appliances, use an RS-232 cable to connect the product's microcomputer and PC, and remote control or monitoring through the PC is possible. was done.</p><p>At this time, since the signal recognition level of the product's microcomputer is in the range of 0 ~ 5V, a separate RS-232 communication chip is provided in the product to match the signal level between the PC and the product.</p><p>On the other hand, as shown in FIG. 1 , when two products, namely, product 1 ( 20 ) and product 2 ( 30 ) are bundled with the receiving end (Rx)/transmitting end (Tx) and connected to one PC 10, the PC 10 ), the internal resistance (Rr1) (Rr2) of the receiving end (Rx) that receives the transmitted signal is very large, more than several hundreds of kohm, while the transmitting end (Tx) of transmitting the signal to the PC (10) has an internal resistance (Rt1) (Rt2) ) is very small, less than a few kohms. Therefore, when a predetermined signal is transmitted from the product 1 (20) to the PC (10), the predetermined signal goes to the transmission terminal (Tx) of the product 2 (30) because the internal resistance of the transmission terminal (Tx) is very small, and is attenuated to the PC (10) is not transmitted accurately.</p><p><maths id="1" align="center"><img file="KR100463533B1_D0001.tif" /></maths></p><p>At this time, when the signal is transmitted from the product 1 (20) to the PC (10), the strength of the signal reaching the PC (10) (V_{pc input}) is the same as in Equation 1, R_rPCis the internal resistance of the receiving end (Rx) of the PC (10), V_iOUTis the voltage level of the signal transmitted, ie, output, from the product 1 (20).</p><p>That is, since the internal resistance (Rt2) of the transmitter 30 of the product 2 is very small, most of the signals transmitted from the product 1 (20) to the PC (10) are transmitted to the transmitter (Tx) of the product 2 (30), and actually Since the signal transmitted to the PC 10 is only one tenth of the signal level transmitted from the product 1 20 , the PC 10 cannot recognize the signal.</p><p>Therefore, since two products cannot be connected to one PC, only one product is connected to the PC 10 to form a network.</p></background-art><tech><p>The network system using the RS-232 communication line according to the prior art has the following problems.</p><p>First, since a separate RS-232 cable for transmission and reception is used between the product and the control PC, the network installation cost is high and the communication line arrangement is complicated.</p><p>Second, when a network is configured with two or more products, signal attenuation occurs and reliable communication cannot be achieved.</p><p>Therefore, the present invention has been devised to solve the above-described problems in the prior art, and it is designed to enable accurate communication without signal attenuation even when two or more products are connected to one controller, with low installation cost and easy arrangement of communication lines. An object of the present invention is to provide a network system.</p></tech>

<p>A network system according to the present invention includes at least two home appliances including a microcomputer and an RS-232 communication chip for RS-232 communication between the microcomputer and the microcomputer; network control means for remotely controlling or monitoring the home appliance; And, the base is connected to the transmitting terminal (Tx) of the network control means or home appliance, the collector is connected to the 'high' level generating power (+15V), and the emitter is connected to the 'low' level generating power (-15V) and 1- A first transistor connected to a line communication bus, a base connected to the emitter of the first transistor and a 1-line communication bus, a collector connected to the 'high' level generating power supply (+15V), and an emitter connected to the ' and an adapter comprising a second transistor connected to a low level generating power source (-15V) and a receiving terminal (Rx) of the network control means or home appliance, wherein the adapter is configured in each of the network control means and the home appliance, Converts the 2-line transmission/reception communication lines (Tx, Rx) of each of the network control means and home appliances to be able to transmit/receive through the 1-line communication bus, and a 1-line communication bus corresponding to the transmission/reception signal level It is characterized in that the signal level is generated for input/output to the corresponding network control means or product.</p><p>Hereinafter, a preferred embodiment of the network system according to the present invention will be described in detail with reference to the accompanying drawings.</p><p>Figure 2 is a block diagram showing the configuration of a network system that connects two products using one communication line according to the present invention, Figure 3 is a detailed circuit diagram of the adapter of Figure 2, Figures 4 and 5 are of Figure 2 This is an impedance equivalent circuit diagram.</p><p>As shown in FIG. 2, the network system according to the present invention provides at least two or more home appliances including a microcomputer and an RS-232 communication chip for RS-232 communication of the microcomputer, and for remote control or monitoring of the products. The PC 40, the PC 40 and each of the products convert the 2-line transmission/reception communication lines to be able to transmit/receive through the 1-line communication bus, and convert 1-line corresponding to the transmission/reception signal level. It is configured to include an adapter 70 that generates a signal level for a line communication bus and inputs/outputs to/from the corresponding PC 40 or product.</p><p>At this time, as shown in FIG. 3, the adapter has a base connected to the PC 40 or the transmitting terminal (Tx) of any one of the products, and a 'high' level generating power (+15V) for the 1-line communication bus to the collector. is applied to the first transistor Q1 to which the 'low' level generation power (-15V) for the 1-line communication bus is applied through a resistor to the emitter, and the power (+15V) is applied to the collector and the emitter is composed of a second transistor (Q2) connected in parallel to a separate 'low' level generation power supply (-15V) for a 1-line communication bus and a PC 40 or a receiving terminal (Rx) of any one of the products, The emitter of the first transistor Q1 and the base of the second transistor Q2 are It is commonly connected to the communication bus.</p><p>The communication process of the network system configured as described above will be described in detail as follows.</p><p>Here, since the signal transmission/reception between the product and the PC 40 and the signal transmission/reception between the products show the same signal flow, the case of transmitting a signal from the PC 40 to the product will be described as an example.</p><p>First, since the first transistor Q1 is turned on when the transmitting terminal Tx signal of the PC 40 is at a 'high' level, a 'high' level generating power (+15V) applied to the collector of the first transistor Q1 It is applied to the base of the second transistor Q2 of each product through this communication bus.</p><p>Therefore, the second transistor Q2 of each product is turned on and the 'high' level generation power (+15V) applied to the collector of the second transistor Q2 is connected to the receiving terminal (Rx) of each product RS-232 communication chip. The level is adjusted so that it can be recognized by the microcomputer and then input to the receiving end (Rx) of the microcomputer.</p><p>Next, when the transmitting terminal Tx signal of the PC 40 is at a 'low' level, the first transistor Q1 is turned off, and thus a 'low' level generation power supply applied to the emitter of the first transistor Q1 ( -15V) is applied to the base of the second transistor Q2 of each product through the communication bus.</p><p>Therefore, the second transistor Q2 of each product is turned off and the 'low' level generation power (-15V) applied to the emitter of the second transistor Q2 is turned off of each product. The signal level is adjusted so that it can be recognized by the microcomputer through the RS-232 communication chip connected to the receiving end (Rx) and then input to the receiving end (Rx) of the microcomputer.</p><p>Looking at the present invention described above, when the PC 40 and the transmission terminal Tx of each product and the communication bus are electrically unidirectional, attenuation of the transmission signal does not occur due to the impedance of the line.</p><p>For example, the emitter of the first transistor Q1 of the adapter connected to the PC 40 is connected to the first and second products through the communication bus, the emitter of the first transistor Q1 of each adapter and the second transistor It is configured to be connected to the base of (Q2), and the output of the transmitting terminal (Tx) of the PC (40) turns on or off the second transistor (Q2) of each product, whereas the first transistor (Q1) is configured to be connected to the base of the transistor. In the end, it does not affect the electrical characteristics of the transmitting terminals Tx of the first and second products.</p><p>Also, looking at the impedance of the circuit, when the output of the transmitting terminal (Tx) of the PC 40 is 'high', as shown in FIG. 4 , since the PC 40 and the internal impedance of each product are connected in parallel, signal attenuation of the communication bus occurs. When the output of the transmitting terminal (Tx) of the PC 40 is 'low', as shown in FIG. 5 , the PC 40 and the internal impedance of each product indicate an independent parallel connection state, so this also attenuates the signal of the communication bus. does not occur</p><p>At this time, in FIG. 4, R3 (not shown) is a resistor connected to the emitter of the second transistor of product 1, R4 (not shown) is a resistor connected to the emitter of the second transistor of product N, and Rr1 (not shown) is PC 40 is the internal resistance of the receiving end (Rx), Rr2 (not shown) is the internal resistance of the product 1 receiving end (Rx), and Rr3 (not shown) is the internal resistance of the product N receiving end (Rx).</p>

<p>The network system according to the present invention has the following effects.</p><p>First, since it is possible to establish a network between one controller and multiple products by using a 1-line communication bus, the overall cost related to system purchase and installation is low and installation is easy, so the competitiveness of products can be improved.</p><p>Second, since it is possible to communicate without signal attenuation even when a network is established by connecting multiple products to one controller, the efficiency and reliability of the network system can be improved.</p>