DVS 510 Series • Reference Information
118
Local echo
Once your computer is connected to the DVS 510, by default Telnet does not display
your keystrokes on the screen. SIS commands are entered blindly, and only the SIS
responses are displayed on the screen. To command Telnet to show all keystrokes, enter
set
local_echo
at the
Telnet
prompt before you open the connection to the scaler.
With local echo turned on, keystrokes and the scaler responses are displayed on the same
line.
Example:
1*1!In1
Out1
All,
where
1*1!
is the SIS command and
In1
Out1
All is the response.
Note that all keystrokes are displayed, even those that should be masked, such as the
password entry. For example, when entering a password with local echo turned on, you see
a display such as
a*d*m*i*n*
, where admin is the keyed-in password and
*****
is the
masked response.
Local echo can be turned off by entering unset local_echo at the
Telnet
prompt. If your
computer is connected to the DVS, and you need to access the
Telnet
prompt to turn
local echo off, enter the Escape sequence (<
Ctrl
+
]
>).
Setting carriage return with line feed
Unless commanded otherwise, Telnet transmits a line feed character only (no carriage
return) to the connected scaler when you press the <
Enter
> key. This is the correct setting
for SIS communication with the scaler. The
Telnet
set
crlf
command forces Telnet to
transmit carriage return and line feed characters when <
Enter
> is pressed. However, if
crlf
is set, the SIS link with the scaler does not function properly.
Closing the link to the scaler
To close the link to the scaler, access the
Telnet
prompt by entering the Escape sequence
(<
Ctrl
+
]
>). At the
Telnet
prompt, enter close.
Help
For Telnet command definitions, enter ? at the Telnet prompt.
Exiting Telnet (Quit command)
Exit the Telnet utility by entering quit at the
Telnet
prompt. If you are connected to the
DVS, access the
Telnet
prompt by entering the Escape sequence (<
Ctrl
+
]
>).
Subnetting, a Primer
A subnet is a
sub
set of a
net
work — a set of IP devices that have portions of their IP
addresses in common. It is not the purpose of this manual to describe TCP/IP protocol
in detail. However, some understanding of TCP/IP subnetting is necessary in order to
understand the interaction of the DVS 510 and the mail server gateway. To understand
subnetting at the level required to install and operate the DVS 510, you must understand
the concepts of a gateway, local and remote devices, IP addresses and octets, and subnet
masks and octets.
Gateways
The DVS 510 Series can communicate with the e-mail server that it uses for e-mail
notification directly (if they are on the same subnet), or its communication can be routed via
a gateway (a computer that provides a link between different subnets).
