2. Communication protocol definitions
2. COMMUNICATION PROTOCOL DEFINITIONS
About
This section describes the de
fi
nitions used in the communications protocol. When the projectors are connected to either RS232 or
LAN you can control the projectors through this ASCII based protocol.
Some commands will generate OSD feedback. This can be stopped by turning off the OSD from the projector’s
menu system or by setting “OSDC” to value 0 (OSD off) or value 1 (OSD show only warnings).
Overview
•
Timing
•
Serial Communications Protocol
•
Examples
2.1
Timing
General timing constraints
Behavior
Constraint
Power on (wake from standby) At least 30 seconds wait after power up complete before sending next command
Command
Response required before sending next command
No response received
At least 2 seconds before re-sending if no response received
Between commands
Minimum 500 ms delay required between commands
After sending 20 commands
Minimum 5 seconds delay required
2.2
Serial Communications Protocol
De
fi
nitions
Like every communication method the serial communication uses a particular protocol (ANSI) which must be respected in order to
allow communication to take place.
The header is ASCII colon ’:’ character.
Use of a separator is optional in the command protocol. The protocol accepts one ASCII SPACE between
fi
elds, or no ASCII SPACE
between
fi
elds.
All acknowledgement protocol use an ASCII SPACE (single) as a separator.
The terminator is ASCII value carriage return (CR)/hex value 0x0D.
The following table gives a summary of the prede
fi
ned communication terms.
Header
Message body
Terminator
Limitations
1 byte
N bytes
1 byte
De
fi
nition
ASCII colon
:
Mnemonic Modi
fi
er Value Target
Carriage Return (Hex 0x0D)
Example
:
POWR1
CR
Header
The header informs the projector (in case of transmission) or the computer (in case of reception) that a new data transfer will take
place.
Message body
The message body de
fi
nes the action to be performed. The message body is built up of several
fi
elds:
601–0381–00 F(L)35, FS35 IR, F85 21/10/2015
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