An Mbus interface control circuit

Abstract

The invention provides an Mbus interface control circuit, comprising a level control reference module which generates a reference voltage according to a control signal sent by a host computer, and sends the reference voltage to a voltage conversion and logic control module. The signal sampling receiving module performs current signal sampling on the voltage conversion and logic control module, andgenerates a data signal transmitted to the host computer according to the sampled signal. A logic current limit protection module generates a control voltage accord to a sampling signal and sends that control voltage to a voltage conversion and logic control module. The voltage conversion and logic control module controls the current signal of the M_BUS interface module to be turned on or off according to the reference voltage and the control voltage, and transmits the current signal to the signal sampling and receiving module. An M_BUS interface module for connecting subsequent MBUS slave circuits. The invention realizes overcurrent protection, power-off and signal transmission control of the MBUS circuit through logic control between hardware circuits, reduces loss to a maximum extent,and greatly improves stability and reliability of the MBUS circuit.

Description

technical field [0001] The invention relates to the technical fields of communication and the Internet of Things, in particular to an Mbus interface control circuit. Background technique [0002] The meter bus (M-Bus) is a new type of bus structure. The main feature of M-Bus is to supply power and transmit serial data at the same time through two non-polar transmission lines, and each substation (confirmed by different ID) is connected in parallel On the M-Bus bus. When M-Bus is used in the energy consumption intelligent management system of various instruments or related devices, relevant data or signals can be collected and transmitted to the concentrator, and then transmitted to the master station through the corresponding interface. The use of M-Bus can greatly simplify the wiring and connection of energy consumption intelligent management systems such as residential quarters and office places, and has the characteristics of simple structure, low cost and high reliabili...

AI Technical Summary

Problems solved by technology

[0004] 1) The strength of the received signal and the stability of the signal output are improved through the logical combination of the pre-filter differential amplifier circuit and the signal output circuit, thereby increasing the number of nodes loaded, improving the load capacity of the circuit and the anti-interference ability of the circuit signal , this scheme does not have the function of abnormal current detection. Once the overcurrent problem such as short circuit occurs in the rear pole, it is easy to cause the circuit of the previous stage to burn out and cannot be recovered; in addition, because the scheme uses multi-stage amplifier circuits and filter circuits, making Only the MBUS receiving circuit is very complicated. If additional sending related circuits are added, the entire MBUS interface will be more complicated, bulkier and more costly.

[0005] 2) The circuit is built with discrete components, and it must cooperate with controllers such as microcontrollers to realize complete overload protection, signal transmission and power supply functions, which makes the entire system respond slowly, and there may be a risk of system hang-up, reliable Low sex

[0006] 3) Complete the M-BUS interface circuit by simplifying the number of discrete components, and realize the MCU data transmission and reception through the control of the triode and voltage dividing resistor. In the circuit design, due to the difference of the triode, this solution will lead to different working circuits. The trigger current is not the same, which affects the consistency of the product, and it is easy to cause the receiving data terminal RX to be in an intermediate state, which leads to the confusion of the sampled data; in addition, the current limiting protection function directly uses the overcurrent protection device. The flow device will protect and disconnect the circuit. This time, the function of the interface circuit must be restored by manually replacing the device. The circuit does not have a self-recovery function, and the practicability is poor.

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