Control method of communication system and air conditioner

Abstract

The application discloses a control method of a communication system and an air conditioner. The communication system comprises a host module and at least one slave module connected with the host module. The control method comprises the following steps: detecting an electrical parameter on a signal line connecting the host module and the slave module when the communication system is in a normal communication state; judging whether the signal line is reversely connected according to the electrical parameter; and switching a communication signal on the signal line if the signal line is reversely connected. Compared with the prior art, the application can detect the electrical parameter on the RX signal of the slave module during the communication between the host module and the slave module, judge whether the signal line is reversely connected according to the detected electrical parameter, switch the TX signal and the RX signal when the signal line is reversely connected, and automatically correct the communication problem caused by the reverse connection of the signal line.

Description

Technical Field

[0001] This invention relates to the field of communications, and in particular to a control method for a communication system and an air conditioner. Background Technology

[0002] Existing multi-split air conditioners that communicate between multiple motherboards via UART have a drawback: easy misconnection. In multi-split communication with one master and multiple slaves, the master's TX signal needs to be connected to the slave's RX signal, and vice versa. During the actual wiring process of connecting the slave to the master, incorrect connections are easily made, leading to communication failures.

[0003] The existing solution cannot accurately determine whether the signal line between the master and slave devices is reversed, and cannot automatically correct it, which will cause communication problems due to the reversed signal line.

[0004] Therefore, how to design a control method for a communication system and an air conditioner that can detect whether the signal lines between the master and slave units are reversed and automatically correct them is a technical problem that the industry urgently needs to solve. Summary of the Invention

[0005] To address the problem in existing technologies that cannot detect whether the signal lines between the master and slave devices are reversed, this invention proposes a control method for a communication system and an air conditioner.

[0006] The technical solution of this invention is to propose a control method for a communication system, the communication system including a host module and at least one slave module connected to the host module, the control method including:

[0007] When the communication system is in normal communication mode, the electrical parameters on the signal lines connecting the host module and the slave module are detected;

[0008] Determine whether the signal line is reversed based on the electrical parameters;

[0009] If so, then switch the communication signal on the signal line.

[0010] Furthermore, the signal line includes a first signal line for transmitting RX signals and a second signal line for transmitting TX signals;

[0011] The electrical parameters are the voltage parameters of the RX signal on the slave module.

[0012] Furthermore, determining whether the signal line is reversed based on the electrical parameters includes:

[0013] Detect whether a low-level signal exists on the RX signal of the slave module;

[0014] If so, then it is determined that the first signal line and the second signal line in the host module and the slave module are positively connected;

[0015] If not, then it is determined that the first signal line and the second signal line in the host module and the slave module are reversed;

[0016] Furthermore, when it is determined that the first signal line and the second signal line in the host module and the slave module are reversed, switching the communication signal on the signal line includes:

[0017] The transmission paths of the RX signal and the TX signal in the slave module are switched so that the communication signals transmitted on the first signal line and the second signal line are opposite to the communication signals transmitted when reversed.

[0018] Furthermore, after switching the communication signal on the signal line, the control method further includes:

[0019] When the communication between the host module and the slave module is abnormal, the communication signals on the first signal line and the second signal line are switched at a preset period.

[0020] Determine whether a low-level signal exists on the RX signal of the slave module;

[0021] If not, then the wiring sequence of the slave module connected to the host module is determined to be faulty, and an alarm is triggered.

[0022] Furthermore, the duration of the preset period is twice the duration of the period of the RX signal.

[0023] Furthermore, before detecting the electrical parameters on the signal line, the control method further includes:

[0024] Detect the total current on the signal lines connecting the host module and the slave module;

[0025] Determine whether the total current is greater than the threshold current;

[0026] If so, the slave module is determined to be overloaded, and the connection between the master module and the slave module is disconnected;

[0027] If not, the communication system is determined to be in a normal communication state.

[0028] Furthermore, each of the slave modules is connected to at least one pull-down resistor, and the slave module determines the address code through the pull-down resistor.

[0029] Furthermore, the host module includes a first main control chip and a first wiring terminal;

[0030] The slave module includes a second master control chip and a second terminal block;

[0031] The host module and the slave module are connected via the first terminal and the second terminal;

[0032] A current-sensing resistor and a low-pass filter circuit connected in series between the first terminal block and the first main control chip are provided.

[0033] The present invention also proposes an air conditioner having a communication system for controlling communication between the indoor and outdoor units, the communication system employing the control method described above.

[0034] Compared with the prior art, the present invention has at least the following beneficial effects:

[0035] 1. This invention can determine whether a signal line is reversed by detecting the electrical parameters on the signal line, and automatically switch the communication signal on the signal line when the signal line is determined to be reversed, so that the signals transmitted on the first signal line and the second signal line are opposite to the signals transmitted when reversed, thereby correcting the problem of reversed signal line connection.

[0036] 2. After switching the communication signals on the first signal line and the second signal line, the present invention further detects whether there is a communication problem between the master module and the slave module under this condition, so as to further determine whether there is a wiring sequence fault in the slave module connected to the master module at this time, thereby improving the reliability of the system.

[0037] 3. Before performing reverse connection detection, the present invention also detects the total current on the signal line to determine whether the slave module mounted on the master module is overloaded, thereby avoiding subsequent abnormal problems caused by overload and improving the safety of the system. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 This is a schematic diagram of the communication system proposed in this invention;

[0040] Figure 2 This is the overall control flowchart of the present invention;

[0041] Figure 3 This is a communication diagram of the host module and slave module when they are communicating normally in this invention;

[0042] Figure 4 This is a communication diagram illustrating a communication error between the host module and the slave module in this invention. Detailed Implementation

[0043] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0044] Therefore, a feature pointed out in this specification is used to describe one feature of one embodiment of the invention, and does not imply that every embodiment of the invention must have the described feature. Furthermore, it should be noted that this specification describes many features. Although certain features may be combined to illustrate possible system designs, these features may also be used in other combinations not explicitly stated. Therefore, unless otherwise stated, the described combinations are not intended to be limiting.

[0045] The principles and structure of the present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0046] Existing multi-unit systems using UART for communication between multiple motherboards suffer from the drawback of easy reverse connection. Furthermore, current technology cannot accurately determine whether the signal lines between the master and slave units are reversed, and cannot automatically correct this, leading to communication problems caused by reversed signal lines. The present invention addresses this by detecting the electrical parameters on the signal lines connecting the master and slave modules to determine if the signal lines are reversed, and switching the communication signal when reversed, thus avoiding communication problems caused by reversed signal lines.

[0047] Please see Figure 3 This is a communication diagram showing normal communication between the master module and the slave module. The master module ( Figure 3 The host in the text refers to the aforementioned host module) and slave module ( Figure 3 Slave 1, Slave 2... (the aforementioned slave modules) each include a first signal line for transmitting RX signals and a second signal line for transmitting TX signals. In the correct connection configuration, the first signal line of the master module is connected to the second signal line of the slave module, at which point the master's TX signal communicates with the slave's RX signal. For example... Figure 3 As shown, under normal circumstances, after the master module calls the slave module, the TX signal sent by the master module is a high-level signal, and the RX signal responded by the slave module is a low-level signal. Under this condition, the master module and the slave module communicate normally.

[0048] Please see Figure 4 This is a communication diagram illustrating a communication error between the master module and the slave module. See [link / reference]. Figure 4 In the slave module 2 section, a reverse connection problem occurs between the master module and the slave module. The first signal line of the master module is connected to the first signal line of the slave module. At this time, the RX signal of the master module communicates with the RX signal of the slave module. Because the slave module cannot receive the TX signal from the master module, the RX signal responded by the slave module is always a high-level signal. Figure 3 In slave unit 2, the RX signal is always kept at a high level.

[0049] contrast Figure 3 as well as Figure 4 When the signal lines of the master module and the slave module are reversed, the RX signal responded by the slave module is always high. Therefore, the presence of a low-level RX signal on the slave module can be directly detected to determine whether the master module and the slave module are reversed. For a communication system with a master module and at least one slave module connected to the master module, the control method proposed in this invention is as follows:

[0050] When the communication system is in normal communication mode, detect the electrical parameters on the signal lines connecting the master module and the slave module;

[0051] Determine whether the signal line is reversed based on the electrical parameters;

[0052] If so, switch the communication signal on the signal line.

[0053] based on Figure 3 and Figure 4 The communication diagram illustrates that, in this invention, the aforementioned electrical parameters are set as the voltage parameters of the RX signal responded to by the slave module, i.e., the level of the RX signal. If the RX signal responded to by the slave module does not have a low-level signal, i.e. Figure 4 The communication diagram at slave unit 2 shows that the signal lines between the master module and the slave module are reversed, and vice versa. In this invention, when the reversed signal lines between the master module and the slave module are determined, a communication signal switch is performed to ensure normal communication between them.

[0054] In this regard, the above logic of "determining whether the signal line is reversed based on electrical parameters" includes:

[0055] Detect whether the RX signal is low;

[0056] If so, then the first signal line and the second signal line in the master module and the slave module are determined to be positively connected;

[0057] If not, then the first signal line and the second signal line in the master module and the slave module are determined to be reversed.

[0058] Here, the first signal line and the second signal line in the master module and the slave module being positively connected means that the first signal line of the master module is connected to the second signal line of the slave module, and the second signal line of the master module is connected to the first signal line of the slave module. At this time, the TX signal of the master module communicates with the RX signal of the slave module, and the RX signal of the master module communicates with the TX signal of the slave module.

[0059] The reverse connection of the first and second signal lines in the master and slave modules means that the first signal line of the master module is connected to the first signal line of the slave module, and the second signal line of the master module is connected to the first signal line of the slave module. At this time, the TX signal of the master module communicates with the TX signal of the slave module, and the RX signal of the master module communicates with the RX signal of the slave module.

[0060] Please see Figure 3 and Figure 4 When connected in the correct orientation, the TX signal of the master module communicates with the RX signal on the slave module. When connected in the reverse orientation, the RX signal of the master module communicates with the RX signal on the slave module. Therefore, normal communication between the master module and the slave module can be achieved simply by switching the transmission paths of the RX and TX signals in the slave module.

[0061] For example, when the master module and slave module are reversed, the wiring is such that the first signal line of the master module is connected to the first signal line of the slave module, and the second signal line of the master module is connected to the second signal line of the slave module. This causes the TX signal transmitted by the master module to communicate with the TX signal of the slave module, and the RX signal transmitted by the master module to communicate with the RX signal of the slave module, resulting in a communication anomaly. In this invention, after switching the transmission paths of the RX and TX signals in the slave module, the first signal line of the slave module is used to transmit the TX signal and is connected to the first signal line in the master module used to transmit the RX signal. This ensures that the RX signal transmitted by the master module communicates with the TX signal of the slave module. Similarly, after the switch, the second signal line of the slave module is used to transmit the RX signal and is connected to the first signal line in the master module used to transmit the TX signal. This ensures that the TX signal transmitted by the master module communicates with the RX signal of the slave module. At this point, the communication logic between the master module and the slave module satisfies... Figure 3 The communication logic shown indicates that the master module and the slave module can communicate normally.

[0062] Specifically, based on the above switching logic, the logic of "switching communication signals on the signal line" includes the following logic:

[0063] Switch the transmission paths of the RX and TX signals in the slave module so that the signals transmitted on the first and second signal lines are opposite to those transmitted when the circuit is reversed.

[0064] Here, since the slave module only transmits RX and TX signals, when it is determined that the first and second signal lines in the master and slave modules are reversed, the signals transmitted on the first and second signal lines in the slave module are opposite to those transmitted when reversed, thus ensuring normal communication between the master and slave modules. Here, "opposite" means different from the previous signal; for example, if the first signal line transmits an RX signal when reversed, switching to the opposite signal means the first signal line transmits a TX signal. The specific logic for maintaining normal communication after the switch has been described earlier and will not be repeated here.

[0065] Please see Figure 1 The slave module has a second master control chip ( Figure 1 The switching logic described above can be implemented through an internal program pre-set in the second master control chip (U1) to ensure normal communication between the master module and the slave module.

[0066] Please see Figure 4 In the reverse connection case, the RX signal is actually always in a high level state. Therefore, in other embodiments of the present invention, the above-mentioned reverse connection judgment logic can also be set as follows:

[0067] Check if the RX signal on the slave module is always a high-level signal;

[0068] If so, then the first signal line and the second signal line in the master module and the slave module are determined to be reversed;

[0069] If not, then the first signal line and the second signal line in the master module and the slave module are determined to be positively connected.

[0070] Furthermore, after switching the communication signals on the signal line, the above control method further includes the following steps:

[0071] When communication between the master module and the slave module is abnormal, the communication signals on the first signal line and the second signal line are switched at a preset period.

[0072] Determine if the RX signal is low.

[0073] If not, the wiring sequence of the slave module connected to the master module is determined to be faulty, and an alarm is triggered.

[0074] This step is used to further determine whether the slave module has a wiring sequence fault, and to further determine whether the communication abnormality is due to a reverse connection problem or a wiring sequence fault. It is only executed after switching the communication signals on the signal lines, and if the communication between the master module and the slave module is still abnormal (if the master module and slave module can communicate normally after switching the communication signals on the signal lines, the communication system is normal, and no further determination is needed in this case), by switching the communication signals on the first and second signal lines at a preset period, it determines whether there is a low-level signal on the RX signal of the slave module, thereby determining whether the slave module connected to the master module has a wiring sequence fault.

[0075] If the result is negative, it indicates a wiring sequence problem. The reason why the RX signal on the slave module is always high is a wiring sequence problem of the slave module. In this case, an alarm needs to be triggered to remind the user that maintenance is required.

[0076] If the result is yes, it means that the master module and the slave module can communicate normally, and there is no wiring sequence problem on the slave module.

[0077] Furthermore, in a preferred embodiment of the present invention, the duration of the preset period is set to be twice the duration of the period of the RX signal.

[0078] Furthermore, the prerequisite for the above judgment logic is "when the communication system is in a normal communication state". Therefore, before detecting the electrical parameters on the signal lines connecting the host module and the slave module, the present invention also includes a step of detecting whether the communication system is in a normal communication state. Specifically, it includes the following logic:

[0079] Detect the total current on the signal lines connecting the host module and the slave module;

[0080] Determine if the total current is greater than the threshold current;

[0081] If so, the slave module is determined to be overloaded, and the connection between the master module and the slave module is disconnected;

[0082] If not, the communication system is determined to be in normal communication status.

[0083] The communication system of this invention includes a master module and at least one slave module. Since the master module has limited operational capabilities, the number of slave modules it can support is also limited. Therefore, the aforementioned detection is necessary to ensure the system's normal operation and security. When the master module is connected to multiple slave modules, current flows from each slave module to the master module. Therefore, this invention determines whether the slave modules connected to the master module are overloaded by detecting the total current on the signal lines connecting the master module and the slave modules. Since the total current is proportional to the number of slave modules it supports, if the total current exceeds a threshold current, the slave modules connected to the master module are considered overloaded; otherwise, the communication system is considered not overloaded and is in a normal communication state.

[0084] The threshold current is set according to the maximum number of slave modules that the host module can support. It is set as the current when the host module supports the maximum number of slave modules. Therefore, when the total current is determined to be greater than the threshold current, it can be determined that the slave modules supported by the host module are overloaded.

[0085] In other embodiments of the present invention, a certain margin can be set for the threshold current. For example, if the current when the host module carries the maximum number of slave modules is A, the threshold current can be set to B, which is slightly less than A. Specifically, B = 0.9A. This ensures that when the total current is greater than the threshold current, the slave modules carried by the host module will not be overloaded immediately, making it convenient for users to adjust the number of slave modules carried by the host module in a timely manner.

[0086] Furthermore, the host module includes a first master control chip, which has a memory containing the addresses of all slave modules. Since there are multiple slave modules in this invention, each slave module needs an address code to distinguish them. This is achieved using pull-down resistors, ensuring that each slave module is connected to at least one pull-down resistor. Figure 1 As shown, each slave module includes m I / O ports, namely I / O-1, I / O-2, I / O-3...I / Om. By assigning pull-down resistors to all I / O ports, there are 2^m combinations, each of which corresponds to an address code, so that each slave module gets a unique address.

[0087] For example, for each I / O port, a pull-down resistor outputs a low level (represented as 0), and no pull-down resistor outputs a high level (represented as 1). For a slave module with three I / O ports (I / O-1, I / O-2, and I / O-3), there are 2^3 = 8 possible combinations. If I / O-1 is connected to a pull-down resistor, while I / O-2 and I / O-3 are not, the slave module's address code can be represented as 011, which serves as the address code for that slave module. By setting the pull-down resistors, the address code can be configured with 8 different values: 000, 001, 011, 010, 100, 101, 110, and 111, thus identifying each slave module using one of these 8 address codes.

[0088] This design method allows for the differentiation of multiple slave modules using a minimal number of address codes, greatly saving I / O port resources (only m I / O ports are needed to differentiate 2^m slave modules).

[0089] Please see Figure 1 In this invention, the host module includes a first main control chip ( Figure 1 The main chip U2) and the first terminal block ( Figure 1 (Port CN2 in the middle);

[0090] The slave module includes a second master control chip ( Figure 1 The main chip U1) and the second terminal ( Figure 1 (Port CN1 in the middle);

[0091] The master module and the slave module are connected via the first terminal and the second terminal;

[0092] A current-sensing resistor is connected in series between the first terminal and the first main control chip. Figure 1 (R4 in the middle), and the low-pass filter circuit connected to the current sensing resistor ( Figure 1 (The circuit part consisting of resistor R1 and capacitor C1).

[0093] Please see Figure 2 The present invention will now be described in detail with reference to the specific process:

[0094] At the beginning, the host (i.e., the host module) pre-stores n slave address codes and sets various parameters. The communication cycle between the host and the slave (i.e., the slave module) is T. The slave monitors the RX signal on its signal line in real time. The host periodically polls its n slave address codes to call them. The slave swaps the TX signal and the RX signal on the signal line at 200%*T (T is the period of the RX signal). At the same time, the host samples the total current on the ground loop in real time (i.e., the total current on the signal line connecting the host module and the slave module).

[0095] After starting, the master unit first connects to the slave unit using the first set of wires;

[0096] When the total current exceeds the set threshold current, the slave connected to the master is determined to be overloaded, and a fault is reported to the user. At this time, the connection between the master module and the slave module needs to be disconnected.

[0097] When the total current does not exceed the set threshold current, the host sends a polling signal to the slave through the second signal line (used to transmit the TX signal). At this time, the slave monitors the level of its RX signal in real time to determine whether there is a low level signal.

[0098] If a low-level signal is present, it indicates that the first and second signal lines in the master and slave are positively connected, and the operation ends after the data is successfully confirmed. Conversely, if the data confirmation fails, the corresponding slave communication data error will be reported.

[0099] If no low-level signal is found, it is initially determined that the first signal line and the second signal line in the master and slave are reversed. The internal program stored in the slave will swap the signal lines of the TX signal and the RX signal. Then, the master will use the second signal line (used to transmit the TX signal) to perform the next round of roll call. The slave will monitor the level status of the RX signal in real time to determine whether there is a low-level signal.

[0100] If so, it indicates that the first and second signal lines in the host and slave are correctly connected at this time, and the program ends after the data is successfully confirmed;

[0101] If not, it is determined that the slave device connected to the master device has a faulty wiring sequence. In this case, the slave device continues to swap the signal lines of the TX and RX signals at 200%T cycles.

[0102] The present invention also proposes an air conditioner having a communication system for controlling communication between the indoor and outdoor units, wherein the communication system employs the aforementioned control method.

[0103] Compared with the prior art, the present invention has at least the following beneficial effects:

[0104] 1. This invention can determine whether a signal line is reversed by detecting the electrical parameters on the signal line, and automatically switch the communication signal on the signal line when the signal line is determined to be reversed, so that the signals transmitted on the first signal line and the second signal line are opposite to the signals transmitted when reversed, thereby correcting the problem of reversed signal line connection.

[0105] 2. After switching the communication signals on the first signal line and the second signal line, the present invention further detects whether there is a communication problem between the master module and the slave module under this condition, so as to further determine whether there is a wiring sequence fault in the slave module connected to the master module at this time, thereby improving the reliability of the system.

[0106] 3. Before performing reverse connection detection, the present invention also detects the total current on the signal line to determine whether the slave module mounted on the master module is overloaded, thereby avoiding subsequent abnormal problems caused by overload and improving the safety of the system.

[0107] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A control method for a communication system, the communication system comprising a host module and at least one slave module connected to the host module, characterized in that, The control method includes: When the communication system is in normal communication mode, the electrical parameters on the signal lines connecting the host module and the slave module are detected; Determine whether the signal line is reversed based on the electrical parameters; If so, then switch the communication signal on the signal line; Both the host module and the slave module include a first signal line for transmitting RX signals and a second signal line for transmitting TX signals. The first signal line of the host module is connected to the second signal line of the slave module, and the second signal line of the host module is connected to the first signal line of the slave module. The electrical parameters are the voltage parameters of the RX signal on the slave module; Determining whether the signal line is reversed based on the electrical parameters includes: Detect whether a low-level signal exists on the RX signal of the slave module; If so, then it is determined that the first signal line and the second signal line in the host module and the slave module are positively connected; If not, then it is determined that the first signal line and the second signal line in the host module and the slave module are reversed.

2. The control method according to claim 1, characterized in that, When it is determined that the first signal line and the second signal line in the host module and the slave module are reversed, the communication signal on the signal line is switched, including: The transmission paths of the RX signal and the TX signal in the slave module are switched so that the communication signals transmitted on the first signal line and the second signal line are opposite to the communication signals transmitted when reversed.

3. The control method according to claim 1, characterized in that, After switching the communication signal on the signal line, the control method further includes: When the communication between the host module and the slave module is abnormal, the communication signals on the first signal line and the second signal line are switched at a preset period. Determine whether a low-level signal exists on the RX signal of the slave module; If not, then the wiring sequence of the slave module connected to the host module is determined to be faulty, and an alarm is triggered.

4. The control method according to claim 3, characterized in that, The duration of the preset period is twice the duration of the period of the RX signal.

5. The control method according to claim 1, characterized in that, Before detecting the electrical parameters on the signal line, the control method further includes: Detect the total current on the signal lines connecting the host module and the slave module; Determine whether the total current is greater than the threshold current; If so, the slave module is determined to be overloaded, and the connection between the master module and the slave module is disconnected; If not, the communication system is determined to be in a normal communication state.

6. The control method according to claim 1, characterized in that, Each of the slave modules is connected to at least one pull-down resistor, and the slave module determines the address code through the pull-down resistor.

7. The control method according to claim 1, characterized in that, The host module includes a first main control chip and a first terminal block; The slave module includes a second master control chip and a second terminal block; The host module and the slave module are connected via the first terminal and the second terminal; A current-sensing resistor and a low-pass filter circuit connected in series between the first terminal block and the first main control chip are provided.

8. An air conditioner, wherein the air conditioner has a communication system for controlling communication between the indoor and outdoor units, characterized in that, The communication system employs the control method as described in any one of claims 1 to 7.

Images