Message Body; Field Description - InFocus LP690 Control Manual

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 algorithm 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.

4.1.2 Message Body

The message body has the following structure:
Byte 0
Operation Type
OpTypeLo
Table 6

4.1.2.1 Field description

Field Name
Operation Type
Function
Value
Table 7
Byte 1 Byte 2
0x00 FuncNum_lo
Field Value
OpTypeLo
0x01 Operation Set. Set current value
0x02 Operation Get. Gets the current value
0x03 Operation Initialize. Initialize the value to default.
Should not be used
0x04 Operation Increment. Increment the value by one
step. Only valid for "Adjust" functions.
0x05 Operation Decrement. Decrement the value by one
step. Only valid for "Adjust" functions.
0x06 Operation Execute. Execute the operation. Only
used for "Execute" operations
FuncNum The actual function number to execute. A list of
usable FuncNum is given in Chapter 9
- Only used by Operation Set. The actual value to set
the operation to. For all other operation actions, this
field is set to 0x0000.
Byte 3
Function
0x00 Opval_lo
Description
Byte 4 Byte 5
Value
Opval_hi