Four-star electronic FS-MM485A is an industrial serial port to Ethernet server which integrates a variety of functions. Users can implement the following functions through parameter configuration: Ordinary serial port to Ethernet server, support TCP or UDP, to achieve transparent transmission of serial port and network port data. MODBUS TCP/RTU standard gateway realizes the bidirectional conversion between MODBUS TCP protocol and RTU protocol. The multi-master station shares the serial port server, and realizes the simultaneous real-time monitoring of a plurality of slave station serial port devices on a slave station serial port device or a serial bus by a plurality of primary stations. As we all know, RS232/RS485/RS422 serial port uses master-slave response mode (also known as query type, polling type) to communicate. Because of the exclusive access characteristic of serial port, there can only be one master station (also known as host computer) on one bus, and it is impossible for multiple master stations to control slave station and data sharing at the same time. Figure 1 / 1 is a typical RS485 communication network topology for a single master station.
The multi-master station sharing serial port server FS-MM485A of four-star electronic adopts time-division technology, and the session time of one-time access serial port is defined as one time slot, and the serial port access of the multi-master station can be realized by reasonably allocating time slots for different master stations. After the time slot session is completed, the other master station will be given a serial port. Make sure all the main stations are able to get the data fairly. as many as 96 main stations can simultaneously access a serial port device or a plurality of serial port devices on a bus, Identical to that use of a single primary station. Figure 1-2 is a multi-master-station RS485 communication network topology using FS-MM485A.
there are some simple products called "serial port sharer" in the market, only a plurality of master stations share a serial port device in time sharing, that is, when a master station accesses a serial port device, other primary stations can only wait, and only after the communication of the waiting primary station is finished, the next master station can communicate with the serial port device, It can only be used in time-sharing devices such as serial printers. And can not be used for the industrial control system to carry out multi-station simultaneous real-time acquisition of data and control the slave station serial port equipment. Features and advantages: Time division technology is used to support up to 96 hosts to access one serial port device or multiple serial port devices on a bus at the same time, and multiple hosts to collect data and control at the same time. Suitable for query RS485/232/422 system (also known as polling, answering system), typical such as MODBUS system. Provide virtual serial port driver software to realize seamless upgrade of existing system and improve control level and grade. Support transparent TCP/IP direct connection and MODBUS TCP/RTU protocol bidirectional conversion, fully support all kinds of configuration software. Strong network fault detection and automatic reconnection mechanism. The industry-level design has strong anti-interference ability, serial port, network port and power port three-way isolation. Wide voltage power supply, not afraid of the influence of power fluctuation, DIN35mm standard guideway installation mode. Like all serial port to Ethernet products, users do not try to use this product for field buses such as PPI,MPI,PROFIBUS, which use RS485 interfaces but do not comply with UART serial communication Application area: Multi-host hot standby operation. Multiple computers can run the same or different acquisition monitoring software at the same time, and do not affect the software operation control. If a computer is paralyzed, the other computers can continue to work without any influence and increase the system reliability by multiple times. Multiple primary stations can be simultaneously supported to access one or more serial port devices. In a typical query system, the A main station can be used for site monitoring, and the B master station is used for central monitoring, and the C master station acquires data to the database. Building / access control / security control system; Power electronics, intelligent instruments; Banking / medical automation system; Coupon trading system; Industrial automation system; a point-of-sale system (pos); Information appliances, Internet of things. The FS-MM485A of the four-star electronic system is designed according to the industry-level standard, supports the automatic recovery of the power-off or the broken-off network, and has a complete indicator light to indicate the working state of the server. The communication interface adopts the electrical isolation and lightning protection processing, and supports 9-40VDC wide-voltage operation and anti-grounding and anti-protection and surge protection. And can be stably operated for a long time in a complex electromagnetic environment. It is widely used in industrial automation system, distributed control system, PLC and various instrument communication, man-machine interface system, intelligent building system and power system. The use of this product and parameter settings are very simple, using IE browser settings, no need for special settings software. Clear concept, users do not need to have complex network knowledge, very suitable for electrical automation, instrument automation and other industrial control professionals.
2. Characteristics and main technical parameters
3. Description of external structure and components
3.1 RS232 socket: the RS232 interface is an isolated DB9M public socket, the effective signal is RXD (receive), TXD (send), RTS (please send), CTS (to allow to send), GND (), the signal arrangement is the same as the standard RS232 interface of the computer, and the surge protector is built in. The definition of signal is shown in Table 3-1.
3.2, RS485 / 422 terminal and power terminal: the working power supply of this product is any DC power supply between voltage 9~40VDC, which is isolated by DC/DC, so the working power supply of this product should be from any equipment without considering the problem of ground supply interference. RS485 / 422 interface has been isolated and built into lightning surge protector. The definition of signal is shown in Table 3-2.
Please install the terminal resistance correctly according to the RS485/422 specification: When the RS485 interface is used, one 120-ohm terminal resistor shall be connected to the RS485 signal terminals D + and D-terminals at the beginning and end of the bus. When using RS422 interface, the RS422 signal receiving terminal RXD at the beginning and end of the bus, and a 120ohm terminal resistance should be connected to each of the RXD- terminals. Note: users can use one of the RS232,RS485,RS422 interfaces at will, connect to which port they want to use, and there is no need for switching or jumper selection, but they cannot be used at the same time. 3.3, Ethernet interface:
3.5, default button: press the button and hold it for more than 3 seconds, and the password of the module will be restored to the factory default setting: empty password (no password); The IP address of the module is restored to the factory default setting: 192.168.1.254, static IP mode, gateway: 192.168.1.1, subnet mask: 255.255.255.0, which is helpful for users to reset the IP address and password of the module to the factory default value when they forget the IP address and password of the module.
4, description of parameter settings
4.1, enter the parameter setting interface: This product uses Windows IE browser to set parameters, without special setting software. The approach is as follows: Connect the network port of the FS-MM485A to the network port of the computer, or to the network port of the Ethernet switch with the network cable, and the other network port of the switch to the computer. Connect FS-MM485A to a DC power supply with arbitrary voltage between 9-40VDC. The IP parameters for setting the computer are as follows: IP address = 192.168.1.X (X ≤ 2 ≤ 2553), subnet mask = 255.255.255.0, gateway = 192.168.1.1. As shown in figure 4 / 1.
Press the Default button on the panel for more than 3 seconds. After the module is restarted, the IP address of the module is restored to the factory default setting:192.168.1.254;Module password reverts to empty password. In the IE browser address bar, enter the IP address of the module: 192.168.1.254, play the exit order input dialog box, at this time, do not need to enter the password, directly click the "login" button to enter the figure 4 / 2 parameter setting interface.
Note: it is necessary to ensure that the IP address of the computer and FS-MM485A is in the same network segment and different, that is, the first three items of the IP address are the same, and the fourth item is different before the computer can access the module. In this case, the IP address of the computer is: 192.168.1.108 / FS ≤ MM 485A IP address: 192.168.1.254; the subnet mask of the two is 255.255.255.0; and the gateway address of the two is 192.168.1.1. The subnet mask of the two is 255.255.255.0, and the gateway address of the two is 192.168.1.1. Cancel button:exit the setting interface without saving parameters. Submit button: Save parameters and restart the module. Each time you set a parameter, you must click the button to save the parameter and restart the module, and the new parameter will take effect. If you change the IP address of the module, you need to enter a new IP address the next time you enter. If you forget the IP address or password, press the Default button to restore to the factory default IP address and password. 4.2. Parameter description:
Note: the serial port parameters of the FS-MM485A set above must be the same as the serial port parameters of the user equipment to which it is connected in order to communicate normally! For, Flow control (flow control when using the RS485 or RS422 interface) must be set to None, when using the RS232 interface, flow control support None,CTS/RTS,XON/XOFF, can be set according to the specific device connected, but most use None. Example: the function of No-Data-Restart=Enable,No Data Restart Time=20, is: if the serial port or network port of the module has no data transmission for some reason (such as interference), the module waits for 20 seconds to restart, which can avoid the "crash" of the module due to interference and other reasons. In general, this feature can be turned off (Disable).
Note:The InstructionTimeout(RS485 command response timeout)and RS485ConflictTimeGap(RS485 conflict detection time)parameter settings are valid only when the communication function of multimaster station is enabled, i.e. EnableMultihost=Yes. These two parameters are related to the baud rate of the user's serial port equipment, the response speed of the serial port equipment, the sending command length and the application software of the user's upper computer. Field setting is required. Four-star electron
5. Application of FS ≤ MM 485A
FS-MM485A is a product that integrates many functions, which can be used as an ordinary Ethernet transit server to realize the two-way transparent transmission of data from serial port to Ethernet, and to support the general Socket operation mode and virtual serial port communication, and can also be used as the standard gateway from MODBUS TCP to RTU to realize the bidirectional conversion from MODBUS TCP to MODBUS RTU protocol. The biggest bright spot of FS-MM485A is that it supports multiple master stations to access one or more RS485/422/232 serial port devices in real time at the same time. 5.1, as a common serial port to Ethernet server General settings when the FS-MM485A is used as a common serial-to-Ethernet server: Serial Settings: The baud rate, the data bits, the Parity, Stopbits, and Flow control must be the same as the serial port parameters of the connected devices. Otherwise, the communication is not allowed. Among them, the flow control of RS485/422 is None, and the RS232 is selected according to the actual situation of the equipment (most None). Advaced Settings (advanced settings): No-Data-Restart (no data restart module) = Disable (no data restart time for); No Data Restart Time (): it is meaningless to set up after prohibition. Multi-host Settings: Protocol = None (no protocol transparent transmission); Enable Multi-host (multi-master station enabled) = No (multi-master station function is disabled); Instruction Time out (RS485 command response time out time): No significance is set after multi-master station function is disabled; RS485 Conflict Time Gap (RS485 collision detection time): It is meaningless to set the function of the multi-master station. The Network Settings (network parameter sets the): Device IP (module IP address): each network device in the same LAN must have different IP address and the same segment address, that is, the first three items of the IP address are the same, and the fourth item is different, such as the 192.168.1.X. Subnet Mask (subnet mask): it must be the same as the subnet mask of the local LAN. For example: 255.255.255.0. Gateway (gateway): must be the same as the local LAN gateway. For example: 192.168 .1.1. Other parameters are set according to different network connection topologies. 5.1.1 TCP point-to-point connection As shown in Fig. 5.1 -1, one module is set to TCP Server, and the other module is set to TCP Client. As the module block of TCP Client, the IP address and port number of the module as the TCP Server are actively connected, and after the TCP connection is established, the TCP indicator on the module is on. At this time, the serial port of the two user equipment can be communicated, just like the serial port of the two user equipment connected with the cable.
The LAN icon in the figure represents a switch in the LAN. When the working mode of the module is set to TCP Server, Destination IP/DSN (target IP or domain name) and Destination Port (target port) are meaningless, and when the working mode of the module is set to TCP Client, the port number (Device Port) setting of the module is meaningless. 5.1.2 TCP point-to-multipoint connection As shown in figure 5.1 ≤ 2, as a module of TCP Server, up to 96 TCP Client modules can be connected. This network topology can replace the traditional RS485 bus network. The user serial port device connected to the TCP Server module is used as the master station, and the user serial port device connected to the TCP Client module is used as the slave station. When the master station sends the data, all the slave stations receive the data; when any slave station sends the data, the master station will receive the data, but the slave station can not transmit the data; this is a typical master-slave RS485 network. .
5.1.3, UDP point-to-point connection. As shown in Fig. 5.1 / 3, the working mode of the two modules is set to connect the IP address and port of each other to each other by the two modules of UDP, so as to establish the UDP connection. The TCP indicator light on the module is lit, and the two user serial port devices can communicate with each other.
5.1.4. UDP multi-point connection Multi-point connection can be realized by using UDP broadcasting. As shown in figure 5.1 / 4, each module in the local area network connects to a broadcast address with the target address of 192.168.1.255 (or 255.255.255.255), which is a special IP address called broadcast address. And the port number of each module and the deconnected target port number are set to the same port number. In this way, each module can receive data from other modules, and this connection can more easily replace the traditional RS485 communication network, which is different from TCP point-to-multipoint connection. Every module in the P-point-to-multipoint connection network is equal, that is, the user can use any device as the master station.
5.1.5. The computer uses the virtual serial port to connect the FS-MM485A module.
The connection between computer and FS-MM485A can use Socket programming or virtual serial port software. The advantage of using virtual serial port software is that users do not need to program. After simply setting up the virtual serial port software in the computer, a virtual serial port can be generated in the computer. At this time, the serial port of the computer is connected with the serial port of FS-MM485A by cable. In this way, the user can use the original application software to communicate with the user serial port device without making any changes. The four-star electronic has the virtual serial port software VCOMM on the product CD. For the use method of the software, please refer to the manual on the CD. The following describes the parameter setting of the computer through the VCOMM virtual serial port software and the FS-MM485A for various connections. The computer makes TCP Client,FS-MM485A as TCP Server, to realize point-to-point connection: Fig. 5.1 / 5 is the setting of connection topology and FS-MM485A, and fig. 5.1 / 6 is the setting of virtual serial port software VCOMM in computer. After the connection is established, the TCP indicator on FS-MM485A is lit. At this time, a serial port COM3, user chooses to use this COM3 serial port in the application software to communicate with the user's serial port device.
The computer makes TCP Server,FS-MM485A as TCP Client, to realize point-to-multipoint connection: As shown in figure 5.1 ≤ 7, computers, as TCP Server, can accept multiple connections as TCP Client modules, and the number of connections is unlimited. This network topology can replace the traditional RS485 bus network, the computer is used as the master station, and the household serial port device connected to the TCP Client module is used as the slave station. When the master station sends the data, all the slave stations receive the data; when any slave station sends the data, the master station will receive the data, but the slave station can not transmit the data; this is a typical master-slave RS485 network. Figure 5.1 / 8 is the setting of virtual serial port software VCOMM as TCP Server in computer.
Both the computer and the FS-MM485A implement point-to-point connections as UDP,:
As shown in figure 5.1 / 9, the working mode of the computer and FS-MM485A is set to connect the IP address and port of each other to each other by the two modules of UDP, so as to establish the UDP connection. The TCP indicator on the module is lit, and the COM3 serial port of the computer can communicate with the user serial port device. Figure 5.1-10 is the setting of the virtual serial port software VCOMM in the computer as the UDP.
Both the computer and the FS-MM485A are used as UDP broadcasts to point to point-to-multipoint connections: Computer can realize point-to-multipoint connection by UDP broadcasting. As shown in figure 5.1 / 11, each device in the local area network, including the computer, connects to a broadcast address (or 255.255.255.255) with the target address of 192.168.1.255. this is a special IP address called broadcast address. And each module has the same port number (8899) and the same target port number (8000) to connect. The computer acts as the master station, connects the FS-MM485A user serial port device as the slave station, when the master station sends the data, all the slave stations All received; when any slave station sends data, the master station will receive it, but the slave station can not transmit the data. If the port number of each module is set to the same number as the unconnected target port number, the computer can not only receive the data sent by other user devices, but also receive the data sent by itself, which is not allowed in some applications. Figure 5.1 / 12 is the setting of virtual serial port software VCOMM as UDP broadcast in computer.
5.2 as the MODBUS TCP/RTU standard gateway MODBUS is a widely used communication protocol in industrial equipment communication. MODBUS TCP is an Ethernet-based communication protocol. MODBUS RTU is a communication protocol based on RS485/ RS422/ RS232 serial port. The two-way conversion of the two protocols can be realized by the FS-MM485A, and the MODBUS TCP master station and the MODBUS RTU slave station, or the MODBUS RTU master station and the MODBUS TCP slave station can be seamlessly connected through the FS-MM485A. 5.2.1 Connect the MODBUS TCP master station and the MODBUS RTU from the station with the FS-MM485A As shown in figure 5.2 / 1, to use the FS-MM485A module to bridge the MODBUS TCP master station with the MODBUS RTU slave station, you need to set the Protocol (protocol) to the working mode of the Modbus TCP to RTU, module to set the TCP Server, port number to the MODBUS TCP proprietary port number 502 (which is not necessary, of course, you can also use any other port number), so that you can set up the connection in the MODBUS TCP application software of the master station computer. The IP address and port number (such as the IP address in this case: 192.168.1.254, port number: 502) and the address of the slave device can access the slave MODBUS RTU device. Suitable for all standard MODBUS equipment and software, such as configuration king and other upper computer configuration software. When using MODBUS TCP master station to bridge RTU slave station, you can turn on the function of multi-master station to realize the communication between MODBUS TCP multi-master station and RTU slave station, please see the following introduction.
5.2.2, connect the MODBUS RTU master station and the MODBUS TCP slave station with FS-MM485A As shown in Fig. 5.2 / 2, the, MODBUS RTU master station is usually RS485/422/232 serial port equipment, such as using the touch screen of serial port, so that the PLC master station with serial port, the computer using serial port and other, MODBUS TCP slave station devices are usually industrial control devices such as PLC with network port. When the Modbus TCP to RTU function is turned on, the module is set to TCP Client, to connect the IP address and port number of the TCP slave station, so that the MODBUS RTU master station can access the MODBUS TCP slave station. When using MODBUS RTU master station to bridge TCP slave station, multi-master station (RTU) communication can not be carried out.
5.3, share serial port server as multiple master stations This feature is the biggest highlight of this product. Whether FS-MM485A uses protocol-free transmission or MODBUS TCP/RTU gateway (connecting MODBUS TCP master station and MODBUS RTU slave station), multi-master station communication can be realized. The shared serial port server FS-MM485A of four-star electronic multi-master station adopts time division technology, which defines the session time of accessing serial port as a time slot, and realizes serial port access of multi-master station by reasonably assigning time slot to different master stations. After the slot session is completed, the serial port will be given up for other master stations. Ensure that all master stations have fair access to data. Up to 96 master stations can access one serial port device or multiple serial port devices on a bus at the same time, and support multiple master stations to collect data and control in real time at the same time, without changing the original soft parts and system configuration. The operation use and use order of each master station. The main stations are exactly the same. Please note that the implementation of multi-master station communication with FS-MM485A supports master-slave response (also known as query type) RS485 network, such as MODBUS. Multiple master station computers are not supported to use PLC programming software to upload, download, monitor and other operations on PLC at the same time, because the communication program of PLC programming software is not entirely written in the way of master-slave response, and involves rewriting the internal program and data of PLC (imagine that one computer is uploading the program from PLC and the other computer downloading the program from PLC at the same time.) Users should use configuration software such as Kingview or touch screen to achieve multi-master station communication. 5.3.1 setting up for multiple master stations to share serial port servers with FS MM 485A FS-MM485A supports the TCP connection of up to 96 master stations, the more the connected master stations, and the slower the response speed, and we think the response speed can meet the general industrial control requirements when the number of the main stations is not more than 4, and the response speed is equivalent to that of the single master station. Settings for FS-MM485A: Such as Device Information (device information), Serial Settings (serial port parameter settings) and so on, please see the previous introduction, do not repeat here. Figure 5.3 / 1 is a screenshot of the settings when FS-MM485A shares a serial port server as a multi-master station, and the main points of the settings are as follows: The IP address of setting FS-MM485A is the same as the first three items of IP address of other devices in the network, and the fourth item is different. Set port number for FS-MM485A, if it is used as Modbus TCP to RTU gateway, port 502is recommended Work Mode (working mode) = TCP Server (TCP server); Protocol (protocol) = None (no protocol transparent transmission) or Modbus TCP to RTU gateway; according to the actual use settings. Enable Multi-host (multi-master station enable) = Yes (turn on multi-master station function); Instruction Time out (RS485 command response time out time) = the field is set according to the actual situation; RS485 Conflict Time Gap (RS485 collision detection time) = the site is set according to the actual conditions;
The master station is the setting at the time of the computer: When the main station is a computer with a network port, the IP address of each computer is set to be a different address under the same network segment. If you use the non-protocol transmission mode, you can install and use the VCOMM virtual serial port software provided with the optical disk, and set the working mode of the virtual serial port software on each master station computer to the TCP Client (TCP client). All of them connect to the IP address and port number of FS-MM485A. After the TCP connection is established, a serial port will be produced on the computer, and the user will choose to use this serial port in his application software to communicate with the user from the station, just like Connect directly from the station device to the motherboard serial port of the computer. If you use MODBUS TCP/RTU gateway, you only need to choose to use MODBUS TCP protocol in the main station computer application software (such as configuration king and other configuration software) to set the IP address and port number of the connected FS-MM485A, and to specify the address of the user slave port device and other related parameters. Settings when the main station is a serial port device: if the main station is a serial port device, such as a touch screen, a master station PLC, a serial port of a computer, and the like, a common serial port-to-Ethernet server needs to be used for connecting the serial port device of the master station and the FS-MM485A,The server is used. At this time, it is necessary to set the serial port to Ethernet server as TCP Client (TCP client), all to connect to the IP address and port number of FS-MM485A, and the use of TCP connection is like connecting the serial port device of the master station directly to the serial port device of the user slave station. 5.3.2 Network connection Topology for Multi-Master Station Communication Figure 5.3 -2 is the topology of the multi-master station no-protocol transparent communication network, and Figure 5.3 -3 is the communication network connection topology of the multi-master station MODBUS TCP to the MODBUS RTU.
5.3.3 several important parameter settings for multi-master station communication The following time parameter settings are very important for multi-master station communication, involving the reliability and response speed of multi-master station communication. These parameters are related to user equipment, application software and serial port baud rate, which need to be set by users according to the actual situation in the field. Instruction Time out (RS485 instruction reply timeout): And the network port of the user sends the command data to the network port to receive the maximum time difference of the instruction data. This parameter is related to the baud rate of the user serial port device, the response speed of the serial port device, the length of the sending instruction, and the like. The adjustment is usually started from 256 ms, so that the communication speed can be improved and the transmission of the large data block can be accommodated. The setting range of this parameter is 32 ~ 8000ms. RS485 Conflict Time Gap (RS485 conflict detection time): The module detects that the RS485 bus is idle at this time before sending data to the bus, this parameter and the baud rate and string of the user's serial port deviceThe response speed of port equipment is related. This parameter is very important, usually adjusted from 150ms, reduce can improve the response speed of communication, increase can improve the stability of communication. The setting range of this parameter is 5 ≤ 255ms. No-Data-Restart (no data restart), No Data Restart Time (no data restart time): This function is similar to the watchdog function and is designed to enhance the reliability of the system. When the serial port or network port does not have data transmission for some reason, the module is restarted after waiting to the set time. This feature is usually disabled, users can decide whether to turn on this feature according to the actual situation of the field, countless according to the restart time setting range: 5 ≤ 1270 seconds. 5.4 remote communication over the Internet FS-MM485A can realize remote communication around the world through Internet, whether using wired broadband or 3G wireless Internet, as long as there is a network can use Internet communication. There are many options for remote communication on Internet, such as port mapping, VPN and so on. No matter which scheme you need to have a router connected to the Internet, in order to solve the problem of IP address of remote access routers through Internet, there are usually the following two ways: To apply to Internet operators for the purchase of fixed IP addresses, this scheme has a higher usage fee. Using dynamic domain name resolution, apply to the dynamic domain name service provider for a free or paid domain name, and use the domain name to replace the IP address, so that no matter how the IP address changes, the domain name will point to the IP address in real time, just as we usually visit the website. At present, there are many dynamic domain name (DNS) service providers, such as peanut shell, which provide free and paid dynamic domain name service, and can consult him about dynamic domain name service and tariff. The user first needs to apply to the DNS service provider for a domain name and register with the router that connects to the server, on the Client side module In the Remote Host IP Input box, enter the dynamic domain name, and set the IP address of the DNS server as the local DNS server IP address to use the domain name for Internet access. Fig. 5.4 / 1 is the communication network topology of FS-MM485A on the Internet. The FS-MM485A connected to the user's serial port device is set to TCP Server, and connected to the Internet through router 1. Computers in different places can be connected to the Internet as long as they are connected to the Internet, and another FS-MM485A set up as TCP Client, needs to be connected to the Internet through router 2. Figure 5.4 / 1 enables a computer to remotely access a user's serial port device over the Internet, or a serial port device such as a touch screen with the Communication between serial port devices of users in different places. Support non-protocol transparent transmission and MODBUS TCP/RTU gateways, as well as multi-master station access.
In this example, the domain name uses the free dynamic domain name of the peanut shell we applied for: fourstar.vicp.cc, router 1 is a router with dynamic domain name resolution function. Enter the account number and password we applied for with the peanut shell company on the router, and you can see the resolved domain name fourstar.vicp.cc.. As shown in figure 5.4 / 2.
Router 1 also needs to make port mapping settings, as shown in figure 5.4 / 3. In this way, when the remote client connects the domain name fourstar.vicp.cc and port 8899 through the Internet, the IP address of the domain name fourstar.vicp.cc (that is, the external network address of router 1) is automatically resolved, and port 8899 accesses the internetwork address of router 1, 192.168.1.254 and port number 8899, thus realizing remote access to FS-MM485A and user serial port devices through the Internet.
Router 2, as a connection client, does not need these settings, as long as it can connect to the Internet. As a client, a computer can surf the Internet through a router, not through a router, or use GPRS,3G,4G,WiFi, as long as it can connect to the Internet. Figure 5.4 / 1 router 1 can also use 3G router, 3G network card to achieve global Internet wireless communication. Wireless communication between modules and PC can be realized as long as they can surf the Internet wirelessly. The setting method of using wireless communication is basically the same as that described earlier, but the use of 3G routers and wireless network cards produced by different manufacturers may be different. Please read the corresponding product manual. When the module is used as the server, it is best to use the 3G router with dynamic domain name function to connect to it. What needs to be brought to the attention of users is that the current mobile TD-SCDMA 3G and Unicom WCDMA 3G network cards use private network IP addresses, can only be used as clients, can not be used as server side to accept client access, telecom CDMA2000 EVDO 3G Internet cards use public network IP addresses, can be used as server or client side, so we recommend the use of telecommunications CDMA2000 EVDO 3G network card.