FSR IT-AS411 Series User Manual
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Example:
The target device to which the Drop String contents are intended may be a EIKI
projector and the user may wish to turn it on, which is the sequence C00 followed by a
carriage return. If the projector is directly connected to the downstream serial port of the
IT-AS411then the Pass-thru-Protocol request will be the following:
{\S} “C00
<0D>”
The above request has the drop preamble directing the Drop String enclosed within
double quotes to the IT-AS411downstream serial link. The IT-AS411 will interpret the
drop preamble as this device being the final forwarding device and will send the string
C00
(the 0D ASCII hex pair represents a carriage return) to its downstream serial
link.
If the projector were connected via two successive IT-AS411devices, or perhaps a
single IT-AS411and a second Pass-thru-Protocol capable device then the request would
be the following:
{\S\S} “C00 <0D>”
If the end target device, that is the one receiving the Drop String, is attached to a
PtP capable device via 4 intervening PtP capable devices and contains a combination of
both ASCII characters and ASCII hex sequences then the (fictitious) command might look
as follows:
{\S\S3\S2\S1\S}
“A more complex example
embedded ASCII hex seqs <01 02 FF 0D>”
The above request addresses 5 PtP capable devices. The first device interprets
the Drop Preamble directing the Drop String to its serial logical link, S. This device strips
off its logical link, the first \S, and sends the remainder out serial logical link S, ie
{\S3\S2\S1\S}
“A more complex example
ASCII hex seqs <01 02 FF 0D>”.
Each succeeding device interprets the Drop Preamble destination, strips off its
address and forwards the remaining request. This occurs until the last device in the Drop
Preamble in which the remaining request is:
{\S}
“A more complex example 55 AB> with multiple embedded ASCII hex seqs <01 02 FF 0D>”. The last device will strip off the Drop Preamble entirely (as nothing remains of it after stripping off \S and parse the Drop String. The parsing will output any non-special
sequences as is and will interpret any ASCII hex sequences and output the corresponding
hex values. Thus for our example above, the final output is: