Serial to Ethernet Connector - "Server" connection settings
"Connection port settings":
Start listening for incoming connections only when local virtual port is open checkbox enables SEC to start listening for all incoming connections only when local virtual port is opened. If not, all the incoming connections are ignored. If this option is unchecked, all the incoming connections will be accepted, not depending on local port status.
Do not buffer size data for fast response checkbox is used for disabling "Nagle algorithm", to achieve maximum speed of response if small packets are transmitted over network, note that this will cause traffic increase. If you are not sure, please, do not modify this option.
Maximum number of connections to server option defines maximum number of clients that can be simultaneously connected to the server at any time. Use this option if you want to restrict the number of connections (for instance if you have limited bandwidth).
Default port settings option allows you to either assign manually predefined serial port settings (for instance, if you have legacy serial port device that has specific parameters) or fetch them automatically from the remote end. Please, note this option is not available (grayed) if you are creating virtual serial port since communication parameters are fetched during handshaking process.
Baudrate defines the rate at which bits are transmitted (bits per second). In the serial port context, "9600 baud" means that the serial port is capable of transferring a maximum of 9600 bits per second. To be able to communicate at the maximum speed, both local and remote ends must be configured to the same baud rate and pass handshake stage before you can successfully read or write data.
Databits defines the number of data bits to transmit. Usually, the transferred bits include the start bit, the data bits, the parity bit (if used), and the stop bits. However, only the data bits carry useful information. You can configure DataBits to be 5, 6, 7, or 8. Data is transmitted as a series of five, six, seven, or eight bits with the least significant bit sent first (little-endian). At least seven data bits are required to transmit ASCII characters. Eight bits are required to transmit binary data. Five and six bit data formats are used for specialized communication equipment.
Parity defines the parity checking type. Parity can be one of the following: none, odd, even, mark, or space. If Parity is none, parity checking is not performed and the parity bit is not transmitted. If Parity is odd, the number of mark bits (1s) in the data is counted, and the parity bit is asserted or unasserted to obtain an odd number of mark bits. If Parity is even, the number of mark bits in the data is counted, and the parity bit is asserted or unasserted to obtain an even number of mark bits. If Parity is mark, the parity bit is asserted. If Parity is space, the parity bit is unasserted.
Stop bits sets the number of bits used to indicate end of a byte. Stop bits could be 1, 1.5, or 2, however almost all contemporary devices are configured to 1 Stop bit. Please, note that both ends of serial port must be configured to transmit the same number of stop bits to work properly.
Flow control defines the Flow control type. Flow control is usually used to ensure that the receiving serial port device can handle all of the incoming data sent to it. Advanced Serial Port Terminal provides the following values you can assign to Flow control: Xon/Xoff (commonly used for asynchronous communication), Hardware and None.
Since version 4.0, port-to-port connection type has been replaced with a more flexible Telnet (RFC 2217) protocol, which enables you to achieve the same functionality as port-to-port connection, additionally providing the ability to communicate with serial devices and applications which support Telnet (RFC 2217) protocol directly.
There are four main functionality features of the Telnet (RFC 2217) protocol:
- The ability for the client to change and send serial port configuration information to the access server. This is needed to ensure the data being transmitted and received is formatted correctly at the byte level.
- The ability for the access server to inform the client of any modem or signal line changes.
- The ability to monitor and operate remotely any serial device.
- The ability to create port-to-port connection via TCP/IP protocol.
"Network protocol settings" let you choose the underlayer protocol to be used for data transmission in your connection:
If you are using Telnet (RFC 2217) protocol to transmit data over network you have additional options to tune:
Notify remote host on local port settings change checkbox tries to change local port settings (Baudrate, Data bits, Flow control, Parity, Stop bits and Signal lines) on client, depending on your values (actual, if client connects via real serial port only). Note, that signal lines will be sent in any case, do not depending on local serial port types.
Allow changing local port settings checkbox is available only when real serial ports are used in connection. If the remote host wants to change your local port settings, he will be allowed to change them.
Send command to keep connection alive option enables you to specify period of time (in msec), after which Serial to Ethernet Connector sends a command to remote end in order to verify connection's integrity and keep the connection alive.
If Use raw data transmission algorithms checkbox is used, you are able to specify the client's access rights to the local COM port which lets you manage communication direction. You can enable or disable port read/write access rights.
Send "Keep alive" every X sec ... if no reply every Y sec
Send "Keep alive" option gives an interlocutor “Keep alive” command if there is no data transfer between the sides during X seconds. An interlocutor must answer this message.
It permits to find possible connection problems and to maintain active connection. Use this option if your device disconnects automatically after a definite time of net inactivity.
Y is an interval of sending “Keep alive” message in case an interlocutor didn’t answer the last “Keep alive” command sent with X sec interval.
Break connection if no activity for (sec)
SEC will break connection if no network activity is observed for a specified period of time.