Since the first PLC was successfully applied to the GM company's auto production line for the first time, PLC has been widely used due to its convenience, reliability, and low price. But PLC is a black box after all, can't observe the control process in real time intuitively, there is a big difference compared with DCS. The development and popularization of computer technology has provided new technical means for PLC. Through the computer, the monitoring process and results of PLC monitoring can be implemented and PLC can be even more powerful. However, each PLC communication medium and communication protocol are different. The following will briefly introduce the main PLC communication media and protocol contents.
US Department of PLC manufacturers Rockwell AB
Rockwell's PLC mainly includes PLC2, PLC3, PLC5, SLC500, ControlLogix and other models, PLC2 and PLC3 are early models, and now more used small PLC is SLC500, medium-sized is generally ControlLogix, and large-scale PLC5 series.
The DF1 protocol is a communication protocol supported by all Rockwell PLCs. The DF1 protocol can transmit data through a serial port medium such as 232 or 422, or can be transmitted through network media such as DH, DH+, DH485, and ControlNet.
AB plc also provides OPC and DDE. RSLogix includes DDE and OPCSERVER in its integrated software. Data can be communicated through the above software.
AB's high-end PLC also provides high-level language programming capabilities, users can also achieve their own communication protocol through programming.
GE
GE is now mainly used in the domestic 90-70 and 90-30 series plc, these two PLCs support SNP agreement, SNP agreement in its PLC manual has the specific content of the agreement.
Now GE's PLC can also be linked via Ethernet, GE's Ethernet protocol content is not open to the public, but GE provides an SDK development kit that can be based on the development kit communication.
European PLC Series Siemens
Siemens series PLC mainly includes its early S5 and current S7-200, S7-300, S7-400 and other types of PLC. The early S5PLC support is 3964R protocol, but because it is now used in China less, with very few modifications. Outside the project, there is very little data communication with it.
S7-200 is a Siemens small PLC, because of its low price in the country has been a large-scale application, support for MPI, PPI and free communication port protocol.
The Siemens 300 PLC supports MPI and can also communicate via PROFIBUS and Industrial Ethernet bus systems and computers. If you want to complete point-to-point communication, you can use CP340/341.
The S7400, as a large Siemens PLC, provides a fairly complete communication function. Can communicate through MPI of S7 standard, can communicate through C- bus, PROFIBUS and industrial Ethernet at the same time. If you want to use point-to-point communication, S7-400 needs to pass CP441 communication module.
The communication protocol of Siemens has not been disclosed. Many configuration softwares including the Zijinqiao configuration software support MPI, PPI and other communication methods. PROFIBUS and Industrial Ethernet generally use Siemens software for data communication.
Schneider (Modicon)
Schneider's PLC model is more and more applications in the country. The communication method mainly supports two communication protocols, MODBUS and MODBUSPLUS.
The MODBUS protocol has been widely used in the industrial control industry, and it is not only a PLC communication protocol. Many smart devices such as smart meters and inverters have been widely used. After further development of MODBUS, there is now a MODBUSTCP method, which is transmitted via Ethernet, and the communication speed is faster.
MODBUSPLUS is faster and farther away than MODBUS. This communication method requires the installation of the SA85 card provided by MODCON on the computer and the driver of the card must be installed to enable communication.
In addition to the above two methods, Modicon's PLC also supports various communication methods such as TCP/IP Ethernet, Unitelway, FIPWAY, FIPIO, AS-I, and Interbus-s.
Japanese PLC
Omron
Omron series PLC is also popularized in China. In terms of communication, OMRON now uses two major communication methods:
HostLink protocol is a communication method based on serial port for data transmission. When the PLC enters the MONITOR mode, the host computer can communicate with the Omron PLC. When communicating with OMRON, it is necessary to pay attention to the time between two communications. If the communication speed is too fast, PLC communication may be abnormal.
ControlLink is a fast communication method of Omron PLC. ControlLink communicates data through the board. There is a data exchange area between the boards. Data is exchanged by the board to complete the data collection function. Use this method to communicate with OMRON's drivers.
Mitsubishi
Mitsubishi PLC's small PLC is widely used in China. Mitsubishi's PLC models are also more, mainly including the FX series, A series and Q series. Mitsubishi series PLC communication protocol is more, each series has its own communication protocol. If the FX series includes communication through the programming port or 232BD, it can also communicate through 485BD. Its A series and Q series can communicate via Ethernet. Of course, Mitsubishi PLC can also communicate via the CC-LINK protocol.
Matsushita
Panasonic PLC and computer can communicate via serial port and Ethernet. The communication protocol it uses is the MEWTOCOL protocol. Like most Japanese PLCs, the MEWTOCOL protocol is relatively simple. Many software, including the Zijin Bridge configuration software, can read data directly from the PLC.
But PLC is a black box after all, can't observe the control process in real time intuitively, there is a big difference compared with DCS. The development and popularization of computer technology has provided new technical means for PLC. Through the computer, the monitoring process and results of PLC monitoring can be implemented and PLC can be even more powerful.
US Department of PLC manufacturers Rockwell AB
Rockwell's PLC mainly includes PLC2, PLC3, PLC5, SLC500, ControlLogix and other models, PLC2 and PLC3 are early models, and now more used small PLC is SLC500, medium-sized is generally ControlLogix, and large-scale PLC5 series.
The DF1 protocol is a communication protocol supported by all Rockwell PLCs. The DF1 protocol can transmit data through a serial port medium such as 232 or 422, or can be transmitted through network media such as DH, DH+, DH485, and ControlNet.
AB plc also provides OPC and DDE. RSLogix includes DDE and OPCSERVER in its integrated software. Data can be communicated through the above software.
AB's high-end PLC also provides high-level language programming capabilities, users can also achieve their own communication protocol through programming.
GE
GE is now mainly used in the domestic 90-70 and 90-30 series plc, these two PLCs support SNP agreement, SNP agreement in its PLC manual has the specific content of the agreement.
Now GE's PLC can also be linked via Ethernet, GE's Ethernet protocol content is not open to the public, but GE provides an SDK development kit that can be based on the development kit communication.
European PLC Series Siemens
Siemens series PLC mainly includes its early S5 and current S7-200, S7-300, S7-400 and other types of PLC. The early S5PLC support is 3964R protocol, but because it is now used in China less, with very few modifications. Outside the project, there is very little data communication with it.
S7-200 is a Siemens small PLC, because of its low price in the country has been a large-scale application, support for MPI, PPI and free communication port protocol.
The Siemens 300 PLC supports MPI and can also communicate via PROFIBUS and Industrial Ethernet bus systems and computers. If you want to complete point-to-point communication, you can use CP340/341.
The S7400, as a large Siemens PLC, provides a fairly complete communication function. Can communicate through MPI of S7 standard, can communicate through C- bus, PROFIBUS and industrial Ethernet at the same time. If you want to use point-to-point communication, S7-400 needs to pass CP441 communication module.
The communication protocol of Siemens has not been disclosed. Many configuration softwares including the Zijinqiao configuration software support MPI, PPI and other communication methods. PROFIBUS and Industrial Ethernet generally use Siemens software for data communication.
Schneider (Modicon)
Schneider's PLC model is more and more applications in the country. The communication method mainly supports two communication protocols, MODBUS and MODBUSPLUS.
The MODBUS protocol has been widely used in the industrial control industry, and it is not only a PLC communication protocol. Many smart devices such as smart meters and inverters have been widely used. After further development of MODBUS, there is now a MODBUSTCP method, which is transmitted via Ethernet, and the communication speed is faster.
MODBUSPLUS is faster and farther away than MODBUS. This communication method requires the installation of the SA85 card provided by MODCON on the computer and the driver of the card must be installed to enable communication.
In addition to the above two methods, Modicon's PLC also supports various communication methods such as TCP/IP Ethernet, Unitelway, FIPWAY, FIPIO, AS-I, and Interbus-s.
Japanese PLC
Omron
Omron series PLC is also popularized in China. In terms of communication, OMRON now uses two major communication methods:
HostLink protocol is a communication method based on serial port for data transmission. When the PLC enters the MONITOR mode, the host computer can communicate with the Omron PLC. When communicating with OMRON, it is necessary to pay attention to the time between two communications. If the communication speed is too fast, PLC communication may be abnormal.
ControlLink is a fast communication method of Omron PLC. ControlLink communicates data through the board. There is a data exchange area between the boards. Data is exchanged by the board to complete the data collection function. Use this method to communicate with OMRON's drivers.
Mitsubishi
Mitsubishi PLC's small PLC is widely used in China. Mitsubishi's PLC models are also more, mainly including the FX series, A series and Q series. Mitsubishi series PLC communication protocol is more, each series has its own communication protocol. If the FX series includes communication through the programming port or 232BD, it can also communicate through 485BD. Its A series and Q series can communicate via Ethernet. Of course, Mitsubishi PLC can also communicate via the CC-LINK protocol.
Matsushita
Panasonic PLC and computer can communicate via serial port and Ethernet. The communication protocol it uses is the MEWTOCOL protocol. Like most Japanese PLCs, the MEWTOCOL protocol is relatively simple. Many software, including the Zijin Bridge configuration software, can read data directly from the PLC.
But PLC is a black box after all, can't observe the control process in real time intuitively, there is a big difference compared with DCS. The development and popularization of computer technology has provided new technical means for PLC. Through the computer, the monitoring process and results of PLC monitoring can be implemented and PLC can be even more powerful.
Diaphragm air pump uses compressed air as the power source. For various corrosive liquids, liquids with particles, high-viscosity, volatile, flammable, and highly toxic liquids, they can all be exhausted. The product operation is safe, reliable and resistant. Corrosive, durable, self-priming, idling without damage, a variety of materials, versatile, simple installation, maintenance-free.
Mini diaphragm air pump,diaphragm air pump,micro diaphragm air pump
Changzhou Yuanwang Fluid Technology Co., Ltd. , https://www.ywfluid.com