Cobalt Digital COMPASS 9284 3G_HD_SD-SDI 8X4 Video Routing Switch - Manual (Page 13)

9284-OM (V1.3) 9284 PRODUCT MANUAL 1-9
Introduction
9284 Functional Description
When a command string is received, it is not acted upon (but rather, is merely
buffered up) until the final trailer character (
! ) character of the command
string is received. At that time, the routing switcher begins to execute the
commands within the string.
The protocol uses only 7-bit ASCII characters. The 8th bit of received
characters is treated as if it is 0. 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 router 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 router, SPACE characters are optional, but if
used may only appear before and after each individual command and not
embedded within an individual command. Within command strings sent from
the router, a single SPACE character appears before and after each individual
command. SPACES may also appear in character strings.
After the command string has been executed, the routing switcher returns the
string “
OK “ (with a single space character before and after the word “ OK ”),
followed by a string of trailer characters (exclamation marks) and a CR
(carriage return, ASCII 0D) character, to the host. This indicates that the
command has executed successfully. If an error occurs within any command
of a command string, the remainder of the command string is ignored and the
router returns the string “
ERROR “, followed by an optional descriptive string
followed by a string of trailer characters and a CR character, to the host. An
error can be caused by an unknown command name or bad arguments to a
command.
The simplest possible command string would be:
**!!
which consists of the leader and trailer characters but no commands between
them. This command string would generate the response:
** OK !!
This can be useful for verifying that the serial link to the router is operational.
In Routing Switchers requiring only one leader/trailer character, the simplest
command string would be:
*!
which would generate the response:
* OK !