10
Equinox ESP-2 OPTO Serial Hub Installation and User Guide
To use the serial port redirection connection method, you must install drivers on the
host computer. See the Release Notes posted on the Equinox web site,
www.equinox.com, for information.
3.2 Telnet Server
The Telnet server connection method allows a user to make a Telnet connection to a
serial port on the ESP-2 hub and then transmit/receive data using the standard Telnet
protocol. This method is also known as reverse Telnet.
When this method is enabled, the Telnet server within the ESP-2 hub will accept a
connection from any valid remote IP address. There is no filtering of remote
addresses. The connection will be accepted only if the port is not already open and in
use by any connection method, including an existing Telnet session on that port. If the
port is currently in use, the connection request will be rejected.
The Telnet session will remain established until the remote client ends the session, the
Telnet TCP socket is broken or the inactivity time-out (if enabled) occurs.
Table 8 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.
For example, a value of 100 indicates that once serial data is received, the
ESP-2 hub will buffer the data until 1 second (100 hundredths of a second) has
elapsed, at which time all data will be sent.
A 0 value indicates that data will be sent as soon as it is available. The default
value is 0 (send immediately). If the buffer becomes half full, the time is
ignored and the data is sent.
Table 8: Telnet Server Connection Method Configurable Items
Item
Description
Enable/
disable
Enables or disables the Telnet server connection method on the port. The
default value is disabled. This method cannot be enabled if the raw TCP client
connection method is already enabled for the port.
Local IP port
number
Specifies the IP port number on which the Telnet server will listen. This value
cannot conflict with the port numbers specified for other enabled connection
methods on either port. Valid values are 1024-65535. The default value is 3001
for port 1 and 3002 for port 2.
Inactivity time-
out
Specifies the length of time before the Telnet session is disconnected if there is
no activity. Valid values are 0-65535 seconds.
For example, a value of 60 indicates the Telnet session will be disconnected if
there is no activity for a period of 60 seconds.
A 0 value disables the inactivity time-out. The default value is 0 (disabled).
Table 7: Serial Port Redirection Configurable Items (Continued)
Item
Description
