5
Communication Protocol
This section describes how to use the communication protocol to control projectors remotely.
When the projects are connected to either RS232 or LAN you can control the projectors through this ASCII based protocol.
Note: Some commands will generate OSD feedback. This can be turned off from the projector’s menu system or by setting
“OSDC” to value 0 (OSD off) or value 1 (OSD show only warnings).
Timing
General timing constraints:
• Wait30secondsafterpoweronbeforesendingnextcommand.
• Waitforresponsebeforesendingnextcommand.
• Minimum2secondsdelaybeforeresendingifnoresponsereceived.
• Minimum500msdelaybetweencommands.
• Minimum5secondsdelayaftersending20commands
Overview
The protocol has the following definition:
HEADER SEPARATOR ADDRESS SEPARATOR MESSAGEBODY TERMINATOR
1 byte 1 byte 1 -3 bytes 1 byte N bytes 1 byte
Field Description Comment
Header ASCII character ‘:’ Required
Separator ASCII character ‘space’ Optional
Address 1 – 3 bytes address Optional
Terminator CR carriage return (0x0D) Required
Message body
The message body structure is as follows:
MNEMONIC SEPARATOR] MODIFIER SEPARATOR VALUES
1 byte 1 byte 1 -3 bytes 1 byte N bytes
Field Description Comment
Mnemonic 4 bytes key identifier, not case sensitive Required
Modifer Single char symbol Optional
Values N bytes value (max 6 bytes) Optional
Target N bytes value (max 4 bytes) Optional
Separator ASCII character ‘space’ Optional
Mnemonic
TheMnemonicis4byteskeyidentier,knowastheASCIIcommand.
Example: POWR, SABS, IDVI
Modifiers
R Relative change. Value given will be relative to the existing value.
Example: :BRIG R10 will increase brightness with 10 steps
A Request acknowledges. This modifier is only used to read back
the result of the command.
Default all commands send acknowledges so this will not be
necessary.
Default all commands send acknowledges so this will not be
necessary.
? Get current value
?M Get maximum value
?N Get minimum value
?D Get default value
?S Get default step value
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