Avocent ESP Serial Hub, Installer/User Manual, Page: 38 / 96

28 ESP Serial Hub Installer/User Guide
Incoming calls
When the Allow Incoming Calls option is enabled, the ESP hub will listen on the specified TCP
port for connection requests from the network. If another call is active, an incoming connection
request will be rejected.
If the Monitor DCD option is enabled, the connection will be rejected if the control signal is
logically low. The connection will be closed if the inbound control signal changes from logically
high to low.
When a TCP connection is active, the ESP hub will raise the outbound DTR signal to indicate that
the connection is valid (which should be seen as inbound DCD by the serial device). If the remote
end breaks the TCP connection, DTR will be lowered to indicate a Carrier Drop to the attached
serial device.
Configuration utility
The configuration utility connection method may be used on any of the ESP serial ports. Using the
internal configuration utility, you may specify attributes of the ESP hub and its serial ports. This
includes enabling serial port connection methods and specifying their configurable items, plus
configuring serial port attributes. The menu-based interface also allows you to configure network
parameters, download and install Flash images, reboot, reinitialize and monitor ESP hub status. For
more information, see Chapter 5, beginning on page 43.
Table 3.9 describes this method’s configurable items for each serial port.
Serial Port Attributes
Each serial port has a set of attributes. You may change the attribute values using any of the
available tools.
• Web interface - see Displaying or Changing Serial Port Attributes on page 33
• Configuration utility - see Displaying or Changing Serial Port Attributes on page 46
• Configuration file - see Port Attributes Command on page 58
Table 3.9: Configuration Utility Connection Method Configurable Items
Item Description
Enable/disable
Enables or disables the configuration utility connection method on the port. (See
Exclusivity and restrictions on page 15.)
The default value is enabled for port 1 and disabled for other ports.
Inactivity time-out
Specifies the length of time before the configuration utility is disconnected if there is no
activity. Valid values are 0-65535 seconds. A 0 value disables the inactivity time-out.
For example, a value of 60 indicates the configuration utility will be disconnected if there
is no activity for a period of 60 seconds.
The default value is 0 (disabled).