Projector Control
2 GENERAL
This document describes the Communication Protocol between a Proxima® Projector and a Computer (Host). By using this connection the Host will be able control the projector.
Þ
This document are HEX command based only and a regular Terminal program like hyperterminal etc. can therefore not directly be used unless the COM port are activated by the user. This document is aimed at control systems in general which is HEX based.
3 FUNCTION TYPE
The Function is grouped in four different function types:
Function type
Execute
State
State String
Adjust
Comments
An execute function executes an action on the projector, i.e. only one state.
An State function performs a set operation from a predefined list of states. Not all values in the range
have to be legal.
As state but returns ASCII strings
An adjust function is characterized by Maximum > Minimum. And all the integer values between Minimum and Maximum are legal.
Table 4
4 PROTOCOL MESSAGES
4.1Message Formats
The message is always divided in a header and a body part:
Message Head (7Byte)
Message Body (6Byte)
4.1.1 Message Head
The message head has the following structure:
Byte 0 |
| Byte 1 | Byte 2 | Byte 3 | Byte 4 | Byte 5 | Byte 6 |
| Magic Number |
| Body size | CRC | |||
0xBE |
| 0xEF | 0x80 | 0x06 | 0x00 | CRC_lo | CRC_hi |
Table 5
All values is in hexadecimal indicated with the leading 0x. The Magic number is used for synchronizing the start of a message. The Body size is set to the number of bytes contained in the Body part of the message.
Currently there is only one type of body so the size is fixed to 0x0006. The CRC field contains the CRC of the message. The CRC algoritm is given in Appendix 1. To disable CRC set CRC_lo=0x00 and CRC_hi = 0x00.
The Message Head – if the CRC are disabled – then looks like the following string:
0xBE 0xEF 0x80 0x06 0x00 0x00 0x00. This Head will be present in all strings sent to the projector from the host.
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