Dell 1200MP Reference Manual page 2

Projector Response Message Table
Value Response Message
0x00 Success
0x01 Invalid Command (on the control command list but not valid. e.g.Card
Reader command while no card reader plug-in)
0x02 Error Command (includes CRC error and unknown commands)
0x03 System Status - Projector ON (Normal Mode)
NACK System Status - Projector OFF (Standby Mode)
NOTE:
Projector Response Lamp Hour
The values for projector response hour are Byte0, Byte1, and Byte2
Value Response Lamp Hour
Byte0 0x2F (the header of lamp hour)
Byte1 LSB (Hex)
Byte2 MSB (Hex)
eg: 800 (3x256+2x16=800) hours ? 0x2F, 0x20, 0x03
Firmware Version Response
Firmware version: 4 Bytes ASCII Code: "V*.*"
V: Version
*: 0-9
Ex: Version 1.5 ? "V1.5" ? 0x00, 0x30, 0x56, 0x31, 0x2E, 0x35(Success, header of FW Version,
4 Bytes ASCII Code: "V*.*")
When the projector is in the standby mode, no acknowledgement (NACK)
response is sent by the projector.