Dual Serial Port Device Server
The IP Serial Server provides the serial device server for Windows hosts to control serial devices located virtually anywhere through a TCP/IP or UDP/IP Ethernet connection. The IP Serial Server has the asynchronous serial port connection on one side, and a 10/100 Mbps Ethernet connection on the other side. It connects devices, such as CNC, weight scales, and scanners. Applications include industrial/factory automation, automatic warehouse control, and hospital/laboratory automation.
The IP Serial Server Windows driver is designed to control the IP Serial Server Ethernet devices. The driver installs a virtual COM on windows which maps the virtual COM port to the IP address of the IP Serial Server device across the network, enabling the Windows applications to access remote serial devices over Ethernet.
IP Serial Server can function as a server or client for both TCP and UDP connection. The application scenarios are direct IP mode, virtual COM mode, and paired mode. In direct IP and virtual COM modes, IP Serial Server should only work as a server. When in the paired mode one IP Serial Server must set as a client and the other must set as a server in both TCP and UDP connection.
• Direct IP Mode
In direct IP connection, applications can communicate with IP Serial Server using TCP/IP or UDP/IP socket connection. The raw data in the IP    packet will be transferred from and to IP Serial Server’ serial port.
• Virtual COM Mode
In the virtual COM mode, the host connects to IP Serial Server through 10/100 Ethernet. The serial device is then connected to IP Serial Server.
Applications work just as if the serial device is connected to host’s COM port, however it is a virtual COM port that convert application’s data   into IP packet. IP Serial Server then converts the IP packet back to serial data. In this mode, IP Serial Server must set to either TCP/server or  UDP/server. The virtual COM driver is a TCP or UDP client. A security feature is built in IP Serial Server. When IP Serial Server works as a server it will allow incoming connection only when remote IP address passes its IP address filtering.
• Paired Mode
Paired mode is also called serial tunneling. Two IP Serial Servers are involved and they must be set to a client and server pair. The remote IP address of the client site must be the same as server’s IP address and IP address of the client site must pass server’s address filtering. Applications do not actually use virtual COM port. They use the regular COM port and host connects to IP Serial Server through a null modem cable as shown below. The paired mode is a quick method to convert a serial connection into an Internet connection without installing any other software on the host.
• Heart Beat
Heart Beat protocol connection provides a reliable communications connection in Virtual COM Port Mode or with Paired Connection Mode. This feature restores the connection if communications are temporarily lost at either end due to loss of power or Ethernet connection.
•Without this feature a device that loses a connection and stops communicating would not be able to reconnect without human intervention. A TCP data connection can be lost when there is a power failure or temporary loss of an Ethernet connection on either the client or server. If a loss occurs the Heart Beat feature will try to reconnect the TCP data connection every five seconds until communications is established again. The Heart Beat feature is available for use in Virtual COM Port Mode and Paired Connection Mode. This is not available when using a UDP