Avocent ESP Serial Hub, Installer/User Manual, Page: 29 / 96

Chapter 3: Connection Methods, Attributes and Configurable Features 19
Raw TCP client
The raw TCP client connection method allows the ESP hub to make a TCP-based connection to a
remote server and then transmit/receive data using standard TCP. The client hub initiates the
TCP session.
When this method is enabled, the raw TCP client will attempt to establish a connection with the
configured server when the connection mode requirement has been satisfied. The TCP session will
remain active until the client closes the TCP socket, the TCP connection is broken, the inactivity
time-out (if enabled) occurs or if the connection mode is
Connect on DCD and the DCD signal
is lowered.
Table 3.4 describes this method’s configurable items for each serial port.
Serial buffering
Specifies the length of time accumulated serial data should be buffered before being sent
to the remote server. Valid values are 0-65535 hundredths of a second. A 0 value indicates
that data will be sent as soon as it is available.
For example, a value of 100 indicates that once serial data is received, it will remain
buffered up to 1 second (100 hundredths of a second), at which time all data will be sent.
If the buffer becomes half full, the time is ignored and the data is sent.
The default value is 0 (send immediately).
Idle TCP
buffering
Enables or disables buffering of received serial data while waiting for a TCP connection to
be established. When enabled, the most recent 20K bytes of data are held in an internal
buffer. After the connection is established, the buffered serial data is sent to the TCP client.
When this option and this connection method are enabled, you may not enable any other
connection method for the port.
The default value is disabled.
Table 3.3: Raw TCP Server Connection Method Configurable Items (Continued)
Item Description
Table 3.4: Raw TCP Client Connection Method Configurable Items
Item Description
Enable/disable
Enables or disables the raw TCP client connection method on the port. (See Exclusivity and
restrictions on page 15.)
The default value is disabled.
Destination IP
address
Specifies the IP address of the raw TCP server. This is a required item; there is no default
value. Only one destination address can be configured for each serial port. The address
cannot be 0.0.x.x, 127.x.x.x, 192.1.1.1, 248-255.x.x.x or the IP address of the ESP hub.