Sierra Video Ponderosa 3G Series Routing Switcher Family with MediaNav - Manual (Page 119)

SIERRA VIDEO
113
Communication
Protocol
Introduction
This section of this manual contains the most common Host Protocol commands. For a more
detailed list of Protocol commands contact the Sierra Video factory.
The protocol uses the 7-bit ASCII character set. The protocol is compact, with few characters
required to cause switch changes to occur. It is also human-readable and thus easy to
understand and use.
All input, output, and level numbers begin at number 1, not 0.
Note:
When writing commands for a “third party” controller, pay careful attention to the levels of control.
Commands are sent to a routing switcher in a group called a command string.
A command string consists of a leader string of asterisk characters (**), zero, or more
commands, and a trailer string of exclamation marks (!!).
When a command string is received, it is not acted upon until the final trailer character (!) of the
command string is received.
Within the command string, certain ASCII characters may be present and are ignored: any ASCII
character whose code is less than the SPACE character (includes all control characters and the
SPACE character) and the DEL (ASCII 7F) character. Alphabetic characters within the command
string may be in either upper-case or lower-case letters. The routing switcher always sends upper
case characters, except for character strings such as input, output, and level names, which may
have lower case characters in them.
When sending commands to the routing switcher, SPACE characters are optional. SPACES may
also appear in character strings, such as input, output, and level names.
Certain commands have character strings that appear as arguments and use a ~ (tilda) character
to delimit the character strings. The use of the tilda varies and will be defined in the individual
commands.
After the command string has been executed, the routing switcher sends the following to the host.
Chapter
12