Condition:New
Type:Logic ICs
A: 10 standard MBUS slaves can be connected
B: 30 standard MBUS slaves can be connected
C: 50 standard MBUS slaves can be connected
D: 80 standard MBUS slaves can be connected
Data circuit design (high speed AD waveform analysis control): mass production
ThThe slave's return current is not limited, and the current identification can be accurately controlled, which is impossible for analog circuits.
There is a bus waveform analysis alarm indicator, as long as our alarm light is not lit, the command sent is correct.
It will definitely be successful! This is also impossible for analog circuits.
We are not pure analog circuits. If you want to copy the board, you can give up, don't waste everyone's time!
one. Product parameters:
Main MBUS interface:
>MBUS output voltage: high level 32V (specially configurable voltage), in line with the MBUS power supply standard (24V-40V) requirements, also considered the pressure drop of the line loss at the site ensures high versatility
>Communication baud rate: 300-19200bps, the waveform is accurate, and there are very few hosts on the market that can support this range at the same time.
>Interface with TVS tube protection to effectively prevent static or high voltage shock
>Support for short circuit and overcurrent protection
RS485 interface
Communication baud rate: 300-19200bps
The bus can support 256 slaves when sending
Interface with TVS tube protection to effectively prevent static or high voltage shock
Power supply input voltage range: 9V-24V
Housing material: flame retardant material
Appearance size: 100*45*29mm
Wiring instructions: see picture
2. Product design goals
The low-cost design of the digital RS485 to MBUS main converter solves the existing problems in one go. Compared with your own research and development, you only need to pay a little more cost, you can save a long time of exploration and field testing, more support will make the product cheaper and more reliable! At the same time, we only sell products and services, will always support you to normal copy!
Another advanced version supports 250mA and 500mA load, performance is stronger, high efficiency, very low heat! Another TTL level module is sold, ultra-small size can be easily integrated into your circuit, if the national network concentrator.
Features:
The core is all digital circuit to ensure the high consistency of the product under various conditions.
High-speed AD chip for signal recognition and accurate transmission and reception signal identification and control, analog circuits can not be compared
·With waveform shaping function - not afraid of RS485 waveform distortion, as long as the input waveform deviation does not exceed 40?
With clutter filtering to effectively filter clutter on RS485 bus
Ultra-high efficiency, very low heat generation, small sampling resistance, small voltage drop, professional knows
The adaptive bus receives the load regardless of the parameters of the MBUS slave will not affect the copy
3. Analysis and solutions to problems at the site
Many people say that RS485 to MBUS is not easy to use. There is a conflicting problem in principle: RS485 and MBUS are single-duplex, and there will be interference in RS485 and MBUS bus. This kind of interference will cause conflict.
For example, when the MBUS receives the signal sent by the slave and receives the clutter sent by the RS485, then the RS485 chip is the receiving state or the transmitting state. If it is a pure hardware circuit or the microcontroller does not control, the RS485 bus and the MBUS The bus will be embarrassed. In fact, there will be communication failure problems in the priority control. Therefore, when the interference exists, it is inevitable to use it. Of course, we have the means to solve these problems. We are born to solve the problem. Please see the application experience analysis at our details:
Unstable copying: When the signal is normal, sometimes it can be copied and sometimes copied. Sometimes it is related to the temperature. When the temperature is high, it can be copied. If it is low, it can't be copied. After replacing the host for a while, it can't be copied.
Diagnosis: The analog circuit is easily affected by the environment. The parameters of different temperature and humidity components are different. The changes of these parameters are difficult to test at the factory. The limit parameters of the factory can only be set in one range. And this range will change with the changes of the environment, the common TI's MBUS main circuit that can be searched online will have this problem.
Our solution: high speed AD waveform recognition, adaptive digital control
Poor compatibility: equipment from a certain manufacturer can be used, but equipment that is connected to another equipment can not be copied, or products that can be connected to two products can be copied, but they cannot be copied when mixed, or the number of slaves can not be copied. To.
Diagnosis: One may be that after the signal is transmitted through multiple hardware conversions, the waveform will be deteriorated due to the influence of the circuit, and some devices will not receive the normal signal; another
It may be that the receiving circuit is poorly compatible, and the current peak-to-peak value on the bus becomes large and will flood the normal signal.
Our solution: high speed AD waveform recognition, adaptive digital control
The success rate of copying is not 100. It can't be copied when copying.
diagnosis:
A may: RS485 bus is prone to various clutter, on the one hand is interference, on the one hand, there are individual RS485 chip performance degradation or damage on the bus, and some are caused by poor performance of counterfeit chips (less genuine) Of course, it is also related to the on-site environment, if the high-voltage impact of the inductive lightning is damaged.
B may: caused by the MBUS slave load change, will cause the data to be sent to the RS485 bus actively, and directly interfere with the entire RS485 bus.
Our solution: AD data circuit, identification waveform filtering clutter, adaptive digital control
Indicator light description
Blue light: running light
◆Normal operation: On for 6mS, off for 244mS
◆Bus interference is too large alarm (may not be able to read the meter): light 210mS, light off 40mS
◆MBUS off output: flash quickly (on for 64mS, off for 64mS)
Just power-on, short-circuit protection, over-current protection, energy-saving mode, and command shutdown from the host computer will trigger
Green light:
◆Flashing: Send data to the RS485 interface after receiving the meter reply
◆Always on: MBUS output is turned off (short circuit protection, overcurrent protection, energy saving mode, and the command from the host computer to turn off will be triggered)
Red light:
◆Flash: Receive the data sent under the RS485 interface, and send the data to the MBUS interface at the same time
◆Always on: RS485 signal line AB is reversed or RS485 interface drive signal is too weak and does not match
Wiring instructions: M, M are BUS interfaces (regardless of positive and negative), A, B are RS485 A, B line interfaces
Built-in TTL interface: support PCB docking, when the module is used
