Can you help me with some questions about DP communication?

乱世煮酒论天下

Can you help me with some questions about DP communication? [Copy link]

There are several issues that I don't quite understand when the inverter and the host computer are performing DP communication, including some software theory and hardware circuit construction issues.

1. What is a communication protocol? I think a communication protocol is a language standard for communication between two or more devices that can send and receive data, just like the communication standard necessary for communication between different races on the earth. It can also be considered a code book for encrypted communication, requiring both parties to agree on the grammar of communication.

2. The communication protocol on the hardware includes voltage logic, positive logic or negative logic, and the corresponding level of positive and negative logic. There are also hardware transmission lines used in communication circuits, including twisted pair, flat cable, coaxial cable, etc.

3. From the hardware communication protocol to the software communication protocol, a meaningful message frame is a series of high and low level changes with a fixed length, that is, the number of high and low levels. The baud rate determines how long the high and low levels are maintained. The shorter the rise and fall time of the high and low levels, the higher the baud rate that can be used. Of course, the baud rate used is also related to other components in the circuit.

These are the three points I can think of. If there is anything else I haven't thought of, please let the forum experts add to it.

Now let's go back to DP communication. What does it mean that DP communication uses the 485 bus? Does it mean that the physical layer of DP communication is the twisted pair of 485 communication? Is the physical layer of 485 communication the hardware transmission line?

DP communication was first proposed by Siemens and is widely used in Siemens PLC. Is there a way to directly connect a computer to a frequency converter that supports DP communication without using a PLC? How is this system communication achieved?

1. First of all, you need software that supports DP communication. What are your recommendations?

2. Secondly, there should be no DP communication port on the computer, but there is a serial port, so a gateway for serial port to DP communication is needed. Do you have any recommendations for this gateway? Can I only use the Siemens gateway? Are third-party compatible ones ok?

3. If solutions to the above two problems are found, what is the message format of DP communication, what does each bit mean, and how to send the frame?

13620203064

I don't know much about it, I thought it was DisplayPort technology

Gen_X

1. The DP used in frequency converters generally refers to Profi-BUS PA. Even if someone says DP, it may be PA, because PA is designed by Siemens specifically for "devices" on the DP network. Therefore, it is generally Siemens PLC, DCS and other controllers.

2. The computer does have a DP card available. The serial port is generally used as PA, not DP. Consult Siemens customer service. It is a dedicated card. It is transferred by a third party, Dalian.......

3.DP protocol is not completely open, but there was a "***" in China 20 years ago. However, it is recommended not to try to ***. It is OK as long as it works for you. You just need to know that it is as easy to use as MODBUS.

But its biggest advantage is that it can directly access the other party's memory without the need for the other party to do a communication program. This is especially true for PA.

大黑哥哥

13620203064 Published on 2024-4-1 11:22 I don’t really understand, I thought it was DisplayPort technology

Do the 4 lanes of the DP protocol need to be controlled to be equal in length? If it is a USB port multiplexed by the DP protocol, do the TX1 and TX2 need to be equal in length?