Extron electronic DVS 510 SA manual Subnetting, a Primer, Gateways

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 subset of a network — 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).

DVS 510 Series • Reference Information 120