EMS device with USB expansion function

Abstract

The invention discloses an EMS device with a USB expansion function. The EMS device comprises EMS main equipment and a plurality of functional modules, all the functional modules are in the first level and are sequentially sequenced according to the sequence A, B, C,..., the functional modules contained in each functional module are in the second level, the functional modules are sequentially sequenced according to the sequence a, b, c,..., all the functional modules with the same second-level serial number are sequentially arranged into groups according to the first-level sequence to form multiple groups, and finally, the multiple groups are sequentially arranged into rows according to the first-level sequence, namely Aa, Ba, Ca, Ab, Bb, Cb, Ac, Bc, Cc,..., and Ab, Ba, Ca, Ab, Bb, Cb, Ac, Bc, Cc,..., Ab, Ba, Ca, Ab, Bb, Cb, Ac, Bc, Cc. The plurality of functional modules are arranged in a row; the function module is used for being connected with an external device, and data transmission is carried out between the EMS main device and the function module and between the EMS main device and the external device through USB signals. The number of the function modules can be flexibly increased or decreased, interface redundancy of the EMS main equipment is avoided, hardware cost can be controlled, and use is flexible.

Description

Technical Field

[0001] The present invention relates to the technical field of EMS, and particularly to an EMS device with USB expansion function. Background Art

[0002] EMS (Energy Management System) is a platform that monitors, analyzes, and optimizes energy usage through digital and intelligent technologies, aiming to improve energy efficiency, reduce energy consumption costs, and support sustainable development.

[0003] Existing EMS devices usually come with a main control module and work in coordination with various external devices with different functions. These external devices establish communication connections with the main control module through the USB protocol. When communicating between an external device and the main control module using the USB2.0 protocol, the seven-layer architecture of USB2.0 needs to be followed. In the case where the external device has its own MCU, the main control module can connect up to five external devices through a USB HUB. If too many external devices are connected, it will lead to a decrease in data transmission efficiency.

[0004] Currently, the connection between external devices and EMS devices is mainly through the USB interface. For other interfaces (such as HDMI, DisplayPort, etc.), if they need to be connected to the EMS device, a conversion circuit needs to be added inside the EMS device and the corresponding interfaces need to be preset.

[0005] However, the interfaces preset in existing EMS devices at the time of factory are difficult to meet the needs of all users at the same time and are prone to interface redundancy. This not only causes the EMS device to not fully adapt to user needs but also may increase unnecessary hardware costs. In addition, integrating too many conversion circuits and various interfaces on the EMS device will also affect the overall volume and aesthetics of the device. Summary of the Invention

[0006] The purpose of the present invention is to provide an EMS device with USB expansion function, which can flexibly expand the USB interface according to external devices with different functions.

[0007] To achieve the above object, the solution of the present invention is: an EMS device with USB expansion function, including an EMS main device and multiple functional modules;

[0008] The EMS main device is provided with a first USB HUB and at least two groups of USB Hosts, one group of USB Hosts is connected to the first USB HUB, and each functional module is provided with a second USB HUB;

[0009] The multiple functional modules include a first functional module and a second functional module. The first functional module consists of four functional blocks, and the second functional module consists of five functional blocks. The second USB HUBs of all the functional modules are connected to the USB Host of the EMS master device. Each functional block within the first functional module is interconnected through the second USB HUB, and each functional block within the second functional module is also interconnected through the second USB HUB;

[0010] All the functional modules are at the first level and are sequentially sorted as A, B, C...

[0011] The functional blocks contained in each functional module are at the second level and are sequentially sorted as a, b, c...

[0012] All the functional blocks with the same second-level serial number are sequentially arranged into groups according to the first-level order, forming multiple groups. Finally, the multiple groups are sequentially arranged into rows according to the first-level order, namely Aa, Ba, Ca, Ab, Bb, Cb, Ac, Bc, Cc..., so that the multiple functional modules are arranged in a row;

[0013] The functional blocks are used to connect external devices. Data is transmitted between the EMS master device, the functional blocks, and the external devices through USB signals.

[0014] In a preferred solution, the master device includes a first housing, a main control circuit board, and main control output contacts. The main control circuit board is disposed inside the first housing, and the main control output contacts are disposed on the first housing;

[0015] The main control circuit board is provided with a main control MCU, a first USB HUB, two groups of USB Hosts, and a first wire. The two groups of USB Hosts are respectively connected to the main control MCU. One group of USB Hosts is connected to the main control output contacts through the first USB HUB and the first wire, and the other group of USB Hosts is connected to the main control output contacts through the first wire.

[0016] In a preferred solution, each functional block includes a second housing, a slave control circuit board, slave control input contacts, and slave control output contacts. The slave control circuit board is disposed inside the second housing, and the slave control input contacts and the slave control output contacts are respectively disposed on the left and right sides of the second housing;

[0017] The slave control circuit board is provided with a slave control MCU, a second USB HUB, a second wire, and a third wire. The slave control MCU is connected to the second USB HUB. One end of the second wire is connected to the slave control input contacts, and the other end of the second wire is connected to the slave control output contacts through the second USB HUB. Both ends of the third wire are respectively connected to the slave control input contacts and the slave control output contacts. The second wire and the third wire are cross-wired at the slave control output contacts.

[0018] Preferably, the first housing of the main device and the second housing of the functional module, as well as the second housings of adjacent functional modules, are snap-fitted and connected by means of a snap and a slot. When the main device is snap-fitted and connected to multiple functional modules, the main control output contact of the first housing contacts the slave control input contact of the second housing. Among two adjacent second housings, the slave control output contact of the front second housing contacts the slave control input contact of the rear second housing.

[0019] Preferably, a power supply circuit is provided on the main control circuit board, and a conversion circuit and a fourth wire are provided on the slave control circuit board of each functional module. The output end of the power supply circuit is connected to the main control output contact through a first wire, the input end of the conversion circuit is connected to the slave control input contact and the slave control output contact through a fourth wire, and the output end of the conversion circuit is connected to the slave control MCU. When the main device is snap-fitted and connected to multiple functional modules, the power supply circuit of the main device is connected to the switching circuit of each functional module through the main control output contact, the slave control input contact and the slave control output contact.

[0020] Preferably, the power supply circuit is a 12V power supply circuit, and the conversion circuit is a 12V to 5V circuit.

[0021] Preferably, the functional module includes an RS485 module, an RS232 module, a DIDO module, a CAN BUS module, and an LTE module.

[0022] Preferably, the first USB HUB is a 1-to-4 USB HUB.

[0023] Preferably, the second USB HUB is a 1-to-2 USB HUB.

[0024] After adopting the above solution, the beneficial effects of the present invention are as follows: The EMS main device of the present invention is provided with a first USB HUB and at least two groups of USB Hosts. One group of USB Hosts is connected to the first USB HUB. Each functional module is provided with a second USB HUB. The multiple functional modules include a first functional module composed of four functional modules in a group and a second functional module composed of five functional modules in a group. The second USB HUBs of all functional modules are connected to the USB Hosts of the EMS main device, enabling the EMS main device to expand its required USB functions internally through the first USB HUB and perform data transmission with the functional modules externally through the USB Hosts. Each functional module among all functional modules is interconnected through the second USB HUB, and the multiple functional modules are arranged in a row. External devices are connected to the functional modules. Users can select the functional modules that match the external devices according to actual needs and achieve data transmission with the EMS main device through these modules. For external devices using non-USB interfaces, since their conversion circuits and corresponding interfaces are integrated on the functional modules, not only the overall volume of the EMS main device is effectively controlled, but also the aesthetics is improved. Moreover, the number of functional modules can be flexibly increased or decreased, making it more flexible in use, avoiding interface redundancy of the EMS main device, and being beneficial to controlling the hardware cost. Description of the Drawings

[0025] Figure 1 It is a schematic block diagram of two groups of USB Hosts of the main device in Embodiment 1 of the present invention externally connecting nine functional modules based on the USB2.0 seven-layer architecture;

[0026] Figure 2 It is a detailed architecture block diagram of two groups of USB Hosts of the main device in Embodiment 1 of the present invention externally connecting nine functional modules based on the USB2.0 seven-layer architecture;

[0027] Figure 3 It is a schematic structural diagram of the functional module installed on the main device by a clamping method in Embodiment 1 of the present invention;

[0028] Figure 4 It is a schematic structural diagram of the right side view of the main device in Embodiment 1 of the present invention;

[0029] Figure 5 It is a schematic structural diagram of the left side view of the functional module in Embodiment 1 of the present invention;

[0030] Figure 6 It is a schematic block diagram of three groups of USB Hosts of the main device in Embodiment 2 of the present invention externally connecting thirteen functional modules based on the USB2.0 seven-layer architecture;

[0031] Figure 7It is a detailed architecture block diagram of the three groups of USB Hosts of the master device in the second embodiment of the present invention externally connecting thirteen functional modules based on the seven-layer architecture of USB2.0.

[0032] Label description:

[0033] 1. EMS master device; 11. First housing; 12. Main control circuit board; 121. Main control MCU; 122. First USB HUB; 123. USB Host; 124. First wire; 125. Power supply circuit; 13. Main control output contact;

[0034] 2. Functional module group;

[0035] 3. Functional module; 31. Second housing; 32. Slave control circuit board; 321. Slave control MCU; 322. Second USB HUB; 323. Second wire; 324. Third wire; 325. Conversion circuit; 326. Fourth wire; 33. Slave control input contact; 34. Slave control output contact;

[0036] 4. Non-USB interface. Detailed implementation manner

[0037] The present invention will be further described below in conjunction with the accompanying drawings and specific implementation manners.

[0038] The present invention provides an EMS device with USB expansion function, as Figures 1 to 7 shown, including an EMS master device 1 and a plurality of functional module groups 2;

[0039] The EMS master device 1 is provided with a first USB HUB 122 and at least two groups of USB Hosts 123, one group of USB Hosts 123 is connected to the first USB HUB 122, and each functional module group 2 is provided with a second USB HUB 322;

[0040] The plurality of functional module groups 2 include a first functional module group and a second functional module group. The first functional module group is composed of four functional modules 3, and the second functional module group is composed of five functional modules 3. The second USB HUBs 322 of all functional module groups 2 are connected to the USB Host 123 of the EMS master device 1. Each functional module 3 in the first functional module group is connected to each other through the second USB HUB 322, and each functional module 3 in the second functional module group is connected to each other through the second USB HUB 322;

[0041] All functional module groups 2 are of the first level and are sequentially sorted in the order of A, B, C...

[0042] Each functional module 3 included in each functional module group 2 is of the second level and is sequentially sorted in the order of a, b, c...

[0043] All function modules 3 with the same secondary serial number are arranged in groups in sequence according to the primary order to form multiple groups. Finally, the multiple groups are arranged in rows in sequence according to the primary order, i.e., Aa, Ba, Ca, Ab, Bb, Cb, Ac, Bc, Cc..., so that multiple function modules 2 are arranged in a row;

[0044] The function module 3 is used to connect external devices. Data transmission between the EMS master device 1, the function module 3 and the external device is carried out through USB signals.

[0045] The present invention adopts a modular design. Users can select corresponding function modules 3 according to external devices with different requirements, which is more flexible in use. For multiple groups of USB Host123 on the EMS master device 1, each group of USB Host123 is externally connected to a group of function modules 3. All function modules 2 are arranged in a row in the above-mentioned order. When multiple groups of USB Host123 transmit USB signals externally, different groups of USB signals are distributed in a cross pattern. During subsequent hardware connections, even if multiple groups of USB Host123 are set on the master device, the master device only needs one interface for transmitting USB signals externally. And the arrangement of different function modules 2 in a row is more conducive to the subsequent installation and deployment of the EMS device.

[0046] Since the function modules 3 of each function module 2 are independent units, when a certain function module 3 fails, only this function module 3 needs to be removed, without affecting the normal operation of other function modules 3, reducing the subsequent maintenance cost.

[0047] For external devices using non-USB interfaces, the corresponding function module 3 is integrated with a conversion circuit 325 and an interface for connection. When an external device using a non-USB interface is plugged into the corresponding function module 3, the external device can be established with a USB communication connection with the EMS master device 1 through the conversion circuit 325. Therefore, the EMS master device 1 does not need to preset too many conversion circuits 325 or interfaces according to different non-USB interface external devices, which can control the overall volume of the EMS master device 1, improve the aesthetics, avoid interface redundancy, and is beneficial to controlling the hardware cost.

[0048] Embodiment 1:

[0049] As Figures 2 to 4 shown, the master device includes a first housing 11, a main control circuit board 12 and main control output contacts 13. The main control circuit board 12 is arranged inside the first housing 11, and the main control output contacts 13 are arranged on the first housing 11;

[0050] A main control MCU 121, a first USB HUB 122, two groups of USB Hosts 123 and a first wire 124 are provided on the main control circuit board 12. The two groups of USB Hosts 123 are respectively connected to the main control MCU 121, one group of USB Hosts 123 is connected to the main control output contact 13 through the first USB HUB 122 and the first wire 124, and the other group of USB Hosts 123 is connected to the main control output contact 13 through the first wire 124.

[0051] In the first embodiment, the main control circuit board 12 is arranged inside the first housing 11, and the main control output contact 13 outside the first housing 11 is used to connect with the functional module 3, and the main control output contact 13 is used to transmit USB signals and power supply to the functional module 3. In the first embodiment, two groups of USB Host 123 are used to connect different functional modules 2. One group of USB Host 123 is also expanded through the first USB HUB 122 to meet the USB function requirements of the EMS host device 1 itself.

[0052] like Figure 2 , Figure 3 and Figure 5 As shown, each functional module 3 includes a second housing 31, a slave control circuit board 32, a slave control input contact 33 and a slave control output contact 34, the slave control circuit board 32 is arranged inside the second housing 31, and the slave control input contact 33 and the slave control output contact 34 are respectively arranged on the left and right sides of the second housing 31;

[0053] The slave control circuit board 32 is provided with a slave control MCU321, a second USB HUB322, a second wire 323 and a third wire 324. The slave control MCU321 is connected to the second USB HUB322, one end of the second wire 323 is connected to the slave control input contact 33, and the other end of the second wire 323 is connected to the slave control output contact 34 through the second USB HUB322, and two ends of the third wire 324 are respectively connected to the slave control input contact 33 and the slave control output contact 34, and the second wire 323 and the third wire 324 are cross-wired at the slave control output contact 34.

[0054] Each functional module 3 of the implementation one is independent, and each functional module 3 is provided with a slave control circuit board 32 inside. The slave control circuit board 32 is provided with a slave control MCU 321 for realizing different functions. After different external devices are connected to the functional module 3, they are scheduled by the slave control MCU 321 inside the functional module 3 to ensure normal communication between different external devices and the EMS main device 1.

[0055] Example 1 uses the USB2.0 protocol for communication, which is also based on the seven-layer architecture of USB2.0. Specifically, the EMS master device 1 in Example 1 is provided with two groups of USB Host123. Since a slave control MCU321 is provided inside each functional module 3, and after being extended by the second USB HUB322, the USB signal is connected to the functional module 3 at the next level. Among them, the slave control MCU321 and the second USB HUB322 of each functional module 3 both belong to a separate layer architecture when calculating the hierarchy. Therefore, each group of USBHost123 can externally connect to five functional modules 3. And one of the groups of USB Host123 in Example 1 has been extended inside the EMS master device 1 through the first USB HUB122, so that this group of USB Host123 can only externally connect to four functional modules 3.

[0056] In Example 1, each functional module 3 is provided with a slave control input contact 33 and a slave control output contact 34, and the second wire 323 and the third wire 324 are cross-wired at the slave control output contact 34, so that the functional modules 3 can be arranged in a row when connected. Specifically, each functional module 3 in Example 1 is provided with a unique SN serial number. Even when each functional module 3 is arranged in a row during connection, the EMS master device 1 can identify the functional module 3 corresponding to each group of USBHost123 according to the SN serial number of each module, and then after sorting according to the "Aa, Ba, Ca, Ab, Bb, Cb, Ac, Bc, Cc..." described above, data transmission is carried out through the USB signal, which can be achieved by those skilled in the art. With such a setting, the functional modules 3 can be connected without considering the connection order, improving the convenience of user use.

[0057] Furthermore, between the first housing 11 of the master device and the second housing 31 of the functional module 3, and between the second housings 31 of two adjacent functional modules 3, they are snap-fitted and connected by a snap-fit and slot method (not shown in the figure). When the master device is snap-fitted and connected to multiple functional modules 3, the main control output contact 13 of the first housing 11 contacts the slave control input contact 33 of the second housing 31, and in two adjacent second housings 31, the slave control output contact 34 of the front second housing 31 contacts the slave control input contact 33 of the rear second housing 31.

[0058] Example 1 adopts the snap-fitting and slot connection method, making the connection between the master device and the functional module 3, and between two adjacent functional modules 3 more convenient and the overall structure more compact. When the master device is snap-fitted and connected to the functional module 3, the main control output contact 13 and the slave control input contact 33, and between the slave control input contact 33 and the slave control output contact 34 are in close contact, which can ensure the stability of data transmission.

[0059] In addition, asFigures 3 to 5 As shown, non-USB interfaces 4 are provided on both the first housing 11 and the second housing 31, enabling external devices to be plugged into the corresponding functional modules 3 through the respective non-USB interfaces 4 to establish a USB communication connection with the EMS master device 1. Of course, in the first embodiment, a display screen can also be set to communicate with the EMS master device 1 (not shown in the figure), and the EMS master device 1 and the output transmission between the respective functional modules 3 can be more intuitively controlled through the display screen.

[0060] As Figure 2 shown, a power supply circuit 125 is provided on the main control circuit board 12, and a conversion circuit 325 and a fourth wire 326 are provided on the slave control circuit board 32 of each functional module 3. The output end of the power supply circuit 125 is connected to the main control output contact 13 through a first wire 124. The input end of the conversion circuit 325 is connected to the slave control input contact 33 and the slave control output contact 34 through the fourth wire 326. The output end of the conversion circuit 325 is connected to the slave control MCU 321. When the main device is snap-connected to the multiple functional modules 3, the power supply circuit 125 of the main device is connected to the switching circuit of each functional module 3 through the main control output contact 13, the slave control input contact 33, and the slave control output contact 34.

[0061] In the first embodiment, power is directly supplied to each functional module 3 through the cooperation of the main control output contact 13, the slave control input contact 33, and the slave control output contact 34, simplifying the power wiring and improving the aesthetics of the entire EMS device. A conversion circuit 325 is provided on each functional module 3 to ensure the normal operation of the functional module 3.

[0062] As Figure 2 shown, the power supply circuit 125 is a 12V power supply circuit 125, and the conversion circuit 325 is a 12V to 5V circuit. In the first embodiment, the 12V power supply of the EMS master device 1 is converted into the 5V power supply required by the functional module 3, which is beneficial to improving the operating stability of the functional module 3. Of course, in other embodiments, this voltage can also be adjusted according to actual requirements.

[0063] Furthermore, the functional module 3 of the first embodiment includes an RS485 module, an RS232 module, a DIDO module, a CAN BUS module, and an LTE module, but is not limited thereto. Users can adopt different functional modules 3 to establish a communication connection with the EMS master device 1, thereby meeting different functional requirements.

[0064] As Figure 2As shown, in the first embodiment, the first USB HUB 122 is a 1-to-4 USB HUB, but not limited thereto, one of the USB HUBs is connected to the functional module 3 as a group of USB Host 123, and the remaining three USB HUBs are used to meet the USB functional requirements of the EMS host device 1. Since one group of USB Host 123 has been expanded using a 1-to-4 USB HUB, the group of USB Host 123 can only connect four functional modules 3 to the outside.

[0065] like Figure 2 As shown, in the first embodiment, the second USB HUB 322 is a 1-to-2 USB HUB, but not limited thereto, one of the USB HUBs of the current-level functional module 3 is connected to one of the USB Hosts 123 of the EMS host device 1, and is connected to one of the USB HUBs of the next-level functional module 3 as the USB Host 123 of the current-level functional module 3. Another USB HUB of the current-level functional module 3 is connected to the slave control MCU 321, which is responsible for the USB communication between the external device connected to the current-level functional module 3 and the EMS host device 1 on the one hand, and the slave control MCU 321 also coordinates and schedules the USB signal transmission between the current-level functional module 3 and the next-level functional module 3 through the second USB HUB 322 on the other hand, to ensure stable data transmission between the EMS host device 1 and each functional module 3 under the USB2.0 seven-layer architecture.

[0066] Embodiment 2:

[0067] The difference between the second embodiment and the first embodiment is that Figure 6 and Figure 7 As shown, one group of USB Host 123 of the main control circuit board 12 of the second embodiment is expanded inside the EMS host device 1 through a 1-to-2 USB HUB to form a second group of USB Host 123 and a third group of USB Host 123, and the three groups of USB Host 123 are all connected to the main control output contact 13 through the first wire 124.

[0068] A second wire 323 and two third wires 324 are arranged on the slave control circuit board 32 of each functional module 3, one end of the second wire 323 is connected to the slave control input contact 33, the other end of the second wire 323 is connected to the slave control output contact 34 through the second USB HUB 322, the two ends of the two third wires 324 are respectively connected to the slave control input contact 33 and the slave control output contact 34, and the second wire 323 and the third wire 324 are cross-wired at the slave control output contact 34.

[0069] Of course, based on the seven-layer architecture of USB 2.0, the first group of USB Host123 is externally connected to five functional modules 3, and the second group of USB Host123 and the third group of USB Host123 can each be externally connected to only four functional modules 3. Therefore, in the second embodiment, the three groups of USB Host123 of the EMS master device 1 can be externally connected to at most thirteen functional modules 3. Users can select different functional modules 3 according to actual needs to connect to different external devices, providing flexible usage.

[0070] Embodiment 3:

[0071] The difference between Embodiment 3 and Embodiment 2 is that in Embodiment 3, one group of USB Host123 on the main control circuit board 12 is extended inside the EMS master device 1 through a 1-to-3 USB HUB to form the second group of USB Host123, the third group of USB Host123, and the fourth group of USB Host123. The four groups of USB Host123 are all connected to the main control output contact 13 through the first wire 124. The specific architecture block diagram is not shown again.

[0072] One second wire 323 and three third wires 324 are provided on the slave control circuit board 32 of each functional module 3. One end of the second wire 323 is connected to the slave control input contact 33, and the other end of the second wire 323 is connected to the slave control output contact 34 through the second USB HUB 322. Both ends of the three third wires 324 are respectively connected to the slave control input contact 33 and the slave control output contact 34. The second wire 323 and the third wire 324 are cross-wired at the slave control output contact 34.

[0073] Of course, based on the seven-layer architecture of USB 2.0, the first group of USB Host123 is externally connected to five functional modules 3, and the second group of USB Host123, the third group of USB Host123, and the fourth group of USB Host123 can each be externally connected to only four functional modules 3. Therefore, in Embodiment 3, the four groups of USB Host123 of the EMS master device 1 can be externally connected to at most seventeen functional modules 3. Users can select different functional modules 3 according to actual needs to connect to different external devices, providing flexible usage.

[0074] The orientation terms mentioned in this specification are defined relative to the structures shown in the respective drawings. They are relative concepts and may therefore change accordingly depending on their different positions and usage states. Therefore, these or other orientation terms should not be construed as restrictive terms.

[0075] The above are only the preferred embodiments of the present invention and do not limit the design of this case. All equivalent changes made according to the key design of this case fall within the protection scope of this case.

Claims

1. An EMS device with USB expansion function, characterized in that: Including EMS main equipment and multiple functional modules; The EMS main device is provided with a first USB HUB and at least two groups of USB Hosts, one group of USB Hosts is connected to the first USB HUB, and each functional module is provided with a second USB HUB; The multiple functional modules include a first functional module and a second functional module, the first functional module is composed of four functional modules, the second functional module is composed of five functional modules, the second USB HUBs of all the functional modules are connected to the USBHost of the EMS host device, each functional module of the first functional module is connected to each other through the second USB HUB, and each functional module of the second functional module is connected to each other through the second USB HUB; All functional modules are at the first level and are arranged in order of A, B, C... The functional modules contained in each functional module are secondary and are arranged in the order of a, b, c... All functional modules with the same secondary serial number are arranged into groups according to the primary sequence to form multiple groups. Finally, the multiple groups are arranged into rows according to the primary sequence, i.e., Aa, Ba, Ca, Ab, Bb, Cb, Ac, Bc, Cc..., so that multiple functional modules are arranged in a row; The function module is used to connect external devices, and data is transmitted between the EMS main device and the function module and the external devices via USB signals.

2. The EMS device with USB expansion function as claimed in claim 1, characterized in that: The main device comprises a first housing, a main control circuit board and a main control output contact, wherein the main control circuit board is arranged inside the first housing, and the main control output contact is arranged on the first housing; A main control MCU, a first USB HUB, two groups of USB Hosts and a first wire are arranged on the main control circuit board. The two groups of USB Hosts are respectively connected to the main control MCU, one group of USB Hosts is connected to the main control output contacts through the first USB HUB and the first wire, and the other group of USB Hosts is connected to the main control output contacts through the first wire.

3. An EMS device with USB expansion function as claimed in claim 2, characterized in that: Each functional module includes a second housing, a slave control circuit board, a slave control input contact and a slave control output contact, wherein the slave control circuit board is arranged inside the second housing, and the slave control input contact and the slave control output contact are arranged on the left and right sides of the second housing respectively; A slave control MCU, a second USB HUB, a second wire and a third wire are provided on the slave control circuit board. The slave control MCU is connected to the second USB HUB, one end of the second wire is connected to the slave control input contact, and the other end of the second wire is connected to the slave control output contact through the second USB HUB, two ends of the third wire are respectively connected to the slave control input contact and the slave control output contact, and the second wire and the third wire are cross-wired at the slave control output contact.

4. An EMS device with USB expansion function as claimed in claim 3, characterized in that: The first shell of the main device and the second shell of the functional module, as well as the second shells of two adjacent functional modules, are snap-fitted and connected by means of snap-fitting slots. When the main device is snap-fitted and connected with multiple functional modules, the master control output contact of the first shell contacts with the slave control input contact of the second shell, and in two adjacent second shells, the slave control output contact of the front second shell contacts with the slave control input contact of the rear second shell.

5. The EMS device with USB expansion function as claimed in claim 3, characterized in that: The main control circuit board is provided with a power supply circuit, and the slave control circuit board of each functional module is provided with a conversion circuit and a fourth wire. The output end of the power supply circuit is connected to the main control output contact through the first wire, and the input end of the conversion circuit is connected to the slave control input contact and the slave control output contact through the fourth wire. The output end of the conversion circuit is connected to the slave control MCU. When the main device is snap-connected with multiple functional modules, the power supply circuit of the main device is connected to the switching circuit of each functional module through the main control output contact, the slave control input contact and the slave control output contact.

6. An EMS device with USB expansion function as claimed in claim 5, characterized in that: The power supply circuit is a 12V power supply circuit, and the conversion circuit is a 12V to 5V circuit.

7. The EMS device with USB expansion function as claimed in claim 1, characterized in that: The functional modules include an RS485 module, an RS232 module, a DIDO module, a CAN BUS module and an LTE module.

8. The EMS device with USB expansion function as claimed in claim 1, characterized in that: The first USB HUB is a 1-to-4 USB HUB.

9. The EMS device with USB expansion function as claimed in claim 1, characterized in that: The second USB HUB is a 1-to-2 USB HUB.

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