User guide

SW USB Series • SIS Programming and Control 23

SIS Programming

and Control

This section describes the connection through which the SW USB switchers can be

configured and controlled remotely via SIS commands, and describes the commands that are

available. Topics include:

• Host-to-Switcher Communications

• Using the Command and Response Table

• Command and Response Table for SIS Commands

The SW USB can be remotely set up and controlled via a host computer or other device (such

as a control system) that is attached to the rear panel RS-232 port (see “Wiring for RS-232

Communication” in the “Installation” section for information on connecting to this port).

You can issue Simple Instruction Set (SIS) commands to the switcher using your computer

RS-232 interface with a communication software program such as Extron DataViewer or

HyperTerminal.

Host-to-Switcher Communications

SIS commands consist of one or more characters per field. No special characters are required

to begin or end a command sequence. When the SW USB determines that a command that

was entered is valid, it executes the command and sends a response to the host device.

Most responses from the SW USB to the host computer end with a carriage return and a line

feed (CR/LF = ]), which signals the end of the response character string. A string is one or

more characters.

Switcher-initiated Messages

When a local event such as a front panel selection takes place, the switcher responds by

sending a message to the host, indicating what selection was entered. No response is

required from the host.

The switcher sends the following copyright message when it first powers on.

where SWn is the switcher model number as well as the number of inputs, and Vn.nn is the

firmware version number.

NOTE: This message is displayed only when power is applied to the switcher while it is

connected to the computer.