STEINWAY LYNGDORF SP-1, Руководство по установке

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Command and Request Formatting
All commands and requests start with the ‘!’ character.
Commands end with a combination of the Carriage Return character (ascii 0x0D, referred to
as <CR> in this document) and Line Feed (ascii 0x0A, <LF>). Often, a single <CR> is used,
but because different systems handle these characters differently, it is also allowed to end
with <LF>, <CR><LF> or even <LF><CR>. In this document, it is expected to be <CR><LF>,
but all of these combinations are allowed.
Requests end with the character ‘?’ and <CR><LF> (or any <CR><LF> combination as
above).
Both commands and requests can have parameters; these are enclosed in parentheses.
Replies to a request are formatted as the request with the reply values as parameters.
Replies always use the <CR><LF> combination of line-end characters.
Commands and requests are not case sensitive.
In addition, it is possible to subscribe to status changes from the device. In this situation,
whenever a status has changed (new source, new voicing etc.) the device will send a status.
This status is formed exactly like a reply to a request, except it is followed by the character '!'
before the <CR><LF> to indicate that this is an asynchronous message, not a reply.
!COMMAND <CR><LF> Command
!COMMAND(param) <CR><LF> Command with parameter
!REQUEST? <CR><LF> Request
!REQUEST(param)? <CR><LF> Request with parameter
!REQUEST(reply) <CR><LF> Reply to a request
!REQUEST(status)! <CR><LF> A status which has changed
Commands and requests which are malformed or have invalid parameters will be ignored. If
a command or request is correct but followed by garbage before the line end character(s),
the command or request will be executed and the garbage ignored.