Siemens PLC topic discussion post

We have an S7-200 system here. The host computer uses Shandong Likong's configuration software and uses PPI communication. After using it for more than a year, the following data communication was interrupted. I checked the information on the Internet and said that the PPI effective communication distance of S7-200 is 50M. I roughly estimated that the actual site is 40M+. Is it a problem of communication distance? Also, how to determine whether this is a problem of communication distance? Then if you want to add a repeater in the middle, what kind of repeater should you choose?

Please tell me how the S7300 uses the MPI protocol to communicate with the host computer. Now I want to add a host computer, how to set it up, and what equipment needs to be added?

Answer to the first floor, if possible, it is best to add a repeater, because his instructions are only 50 meters. When you use it, you must leave at least a general margin to ensure that the control system can work well for a long period of time.

Answer on the second floor, hello, you can use Siemens' MUDBUS protocol. Just add RS232 to RS485 on the computer, set the address, and communicate with the host computer. The theoretical distance is 1200 meters.

Answer from Floor 3: If you need a computer, you need to buy an MPI cable and an MPI card. The computer must have host computer software.

If it is a USB/MPI cable, use Ethernet OPC connection, add computer, software, and then perform OPC settings.

Can I use wincc and step7 to run simulations on my computer? Because Siemens hardware is too expensive. :)

Answer on the second floor. It has been used for a year, which means it is not a problem of communication distance. It is better to check the cable.

Answer a few questions: The communication port of S7-200 is non-isolated RS485. It is not a long-distance drive type. This means that whether you use PPI protocol, Modbus protocol, or Freeport protocol, the theoretical limit of communication distance is 50 meters. It cannot be 1200 meters just because you use Modbus. How far Modbus can go usually depends on what kind of communication link the physical layer is. The usual driving distance of isolated RS485 is 1200 meters, but it is not applicable on S7-200. However, the Germans are somewhat conservative, and many indicators are relatively conservative in nominal terms. So,,, I have used it before, and the communication is normal and stable over 70 meters. If you really need to go a long distance, you can add an additional RS485 repeater to the 200 communication port. Each time a repeater is added, the communication distance can be extended by about 1,200 meters. You can use Siemens' RS485 Repeater. Advantech or Moxa can also be used. It should be noted that non-Siemens devices do not support special rates such as 187.5K. If the host wants to add a computer to communicate with the 300, each computer needs to add a CP5611 MPI card, an MPI cable, or a DP cable, and then the corresponding HMI monitoring software. Programming cables are not recommended. . . The first is the distance problem. The programming cable is not long enough. The longest of 232 is 15 meters, and the cable brought to you by USB is only 5 meters long. The MPI port section needs to draw power from the MPI port of the CPU, so it is not suitable to connect an additional extension cable. Second, there are almost always problems with the use of programming cables for a long time. It turns out that some comrades used programming cables to save money. Instead of using MPI card. During long periods of non-stop use, the "bump" in the middle of the cable - the converter part - gets very hot. Occasionally, the connection may fail and data may be lost.

I have been exposed to Siemens DCS system in the acid regeneration device of a steel plant before. Due to confidentiality issues, the construction party does not have much contact with the system configuration, and the system manufacturer will not disclose too much. At that time, I only knew that it seemed to be an S7-200 system. WINCC was used for system editing and configuration. The accompanying operating system must be installed on the original machine with a key (because I have little contact with DCS, I don’t know if this statement is correct).

How to use wincc to display the S7200 Siemens system.

Regarding the Siemens PCS7 system, a CPU above CPU 414-3 can be used as a DCS system. Therefore, S7-200 cannot be used as the master controller of Siemens DCS. Siemens software, supporting operating systems, etc. do not require the original system, and can be installed on the original Siemens industrial computer. This post was last edited by qiaopeng1231 on 2009-3-30 20:02 ]

What is the difference between compressed archives and fast archives in process value archives? 1. Is there any difference between compressed archives and fast archives in process value archives? I know their definition. Quick archive is also compressed. What is the difference from compressed archive? 2. Set the storage location of the process value archive to "main memory". After activating the archive screen, new data files and log files will be added to the fast archive and slow archive folders under the archivemanager folder in WinCC, and set to "hard disk". Because it is the hard disk of the database, the above-mentioned data files and log files will definitely be added. Please experts explain it to me, please wait.

SIEMENS's DCS is called PCS7. Its base is actually SETP7+WINCC, but its function is higher than SETP7+WINCC. First of all, it is graphical programming. It can be programmed with CFC and SFC to copy the relevant data. Function blocks with the same logic require a CPU of 416 or above. The s7200 cannot be used as a DCS, but the S7200 can communicate with WINCC. The S7200 also has an Ethernet module, but the s7200 is a small system, and generally few people do this!

There is a small system that uses an S7300 controller and the human-machine interface is Wincc. According to my understanding, the communication between them can use TCP/IP (I have never used S7, only CTI to communicate with Wincc). However, I saw that the engineer in charge of planning used OPC communication. I don’t understand it. It seems a bit redundant, because Wincc itself has SQL. I hope experts can give me some advice. This post was finally posted by carefree456 on 2009-3-30 15:49 Edit ]

Siemens has a real DCS, that is, the Teleperm system, but it has been eliminated. It is now called the SPPA T3000 system, which is used in power plants. The price of PCS7 is very advantageous! Ha ha

8# huchenzeng Use plcsim

16# carefree456 siemens 300 and wincc communication: If Ethernet communication is used, OPC must be used. Currently, I have not heard of a controller and the host computer using Ethernet to communicate without OPC.