GENERIC PROTOCOL
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“N”: Input Status Inquiry
The command "
N
" requests that matrix status information for a single input be returned to the
host. This command is only useful on those router levels that allow an input to be connected to at
most one output. The status information is sent as a “Y” command or a sequence of L “X”
commands, where L=number of levels that allow an input to be connected to at most one output
(each such level generates a single “X” command of status). Thus, a 6-level router with three
single-output-per input levels would generate 3 “X” commands of status command output. A
router that has
all of its levels
as single-output-per-input may return a single “Y” command instead
of individual “X” commands if all of the levels are connected to the
same output
. The “X” and “Y”
commands are formatted exactly as with the "
O
" command.
For example, the command:
**N4!!
to a router might have the following three commands as its response:
** X12,4,2 X-,4,3 X0,4,4 !!
giving the status of levels 2, 3, and 4 (level 1 presumably not being a single-output-per-input
level). Note that on level 3 the ë-ë (dash) indicates that the input is disconnected, and on level 4
the 0 indicates that the connection to the input is either unknown or that input does not exist or is
not available on that level.
If the router has only one level, or if all levels are connected the same, it might instead use the
Y
command. For example:
** Y12,4 !!
“S”: Status Inquiry
Use command S to request that status information be returned to the host. The status information
is sent as a string of L x O substrings, where L = number of levels and O = number of outputs.
Each level/output combination generates a single substring of status. Thus, a 21-level 16 output
router would generate 2x16 = 32 substrings of status command output. The length of each
substring depends on the size of the particular switcher involved. Larger switchers use bigger
numbers for inputs, outputs, and levels.
The first substring of status is for level 1 output 2, etc.; however, each substring contains the level
and output numbers, so the sequence in which the data is sent is not important). The first
characters of each substring are a space followed by “X”, then the output number, a comma
character, the input number connected to the output (or 0 if no connection exists), another
comma, and finally the level number at which the input-output pair is connected. For example, the
command:
**S!!
might have the following two substrings at the beginning of its response:
**x01, 12, 1 x02, 02, 1!!