The serial server is like a microcomputer with a CPU, real-time operating system, and TCP/IP protocol, which is convenient to transmit data between serial ports and network devices. In the process of using the serial port server, generally following the operation manual can basically solve the problem. However, some abnormal faults will still occur in the actual operation.
1. Using the converter setup program, the device cannot be found
① Since the converter setting program is set using the UDP protocol, it is generally possible that the firewall of the anti-virus software blocks the UDP request, resulting in the device not being able to be found.
② Sometimes customers have turned off anti-virus software such as Rising and Norton, but still cannot find the device. In this case, it is possible that the firewall that comes with Windows XP blocks UDP requests. If you want to turn off the firewall, please follow the steps below. Follow the steps below: Right-click “Network Neighborhood”, select “Properties”, right-click “Local Area Connection”, select “Properties”, then select the “Advanced” option, click “Settings”, enter the relevant page, and close the firewall.
③ Turn off all firewalls. If you still can’t find the device, you must find a network administrator, because in this case, the IP address set by the serial port server may conflict with the IP address of the computer in the LAN, which may also cause the Device could not be found. It may also be because the network administrator manages the local area network and does not allow unregistered IP addresses. The MAC address runs in the local area network, and the network administrator can be required to open it.
2. After the converter is installed, it is found that the TCP connection cannot be established
① It is possible that the firewall blocks the TCP connection and prevents it from establishing a connection. The solution can be solved by referring to some of the above methods.
② The IP address may be set incorrectly. If the converter is used as the client, the IP address of the server is the IP address of the computer or the network device that communicates with the converter. If the converter is used as the server, use the “connection of the virtual serial port” When managing the system”, there is a “converter as server-side” setting in the setup wizard, fill in the IP address and port number of the converter.
③ When using a virtual serial port, you must select “Use virtual serial port” in “Serial port parameter setting” of “Converter Setting Program”. If this option is not selected, the connection management system cannot establish a TCP connection. But if the virtual serial port is not used, if the program is directly based on WINSOCKET, this option must be removed, otherwise, the data will appear garbled.
3. A TCP connection is established, but cannot communicate
This situation is generally reflected in the use of virtual serial ports, which is more common in the case of 485 to TCP/IP. Under normal circumstances, the communication protocol of the 485 bus is to achieve point-to-multipoint communication through polling. If the host If there is not responding to the slave machine within a specified period of time, the master machine will consider that the slave machine does not exist, because our default parameter is a certain delay, so modifying the delay can solve this problem. That is, This problem can be basically solved by setting the minimum network sending time and network maximum sending bytes to 0,0 in the “serial port parameter setting” of the “converter setting program” of the serial port server.