
— 8 —
2-6. Communication Rules
• INDEX NUMBER of PROJECTOR shall be set to ‘01’.
• After transmission of a Command to PROJECTOR, CONTROLLER shall not send the next Command
before receiving Return Data ( CMD1=10 hex ) from PROJECTOR. If not, any Data is not transmitted
from PROJECTOR, neither any Error Code.
• In case of a communication error, PROJECTOR ignores all Data sent so far, and transmits ‘NAK’ to
CONTROLLER as a Return Data.
• If unidentified Command is transmitted or Data is not acknowledged by PROJECTOR, PROJECTOR
transmits ‘NAK’ to CONTROLLER as a Return Data.
• While a signal inputted to PROJECTOR is not stable ( where 7 SEG LED indicates ‘10’ ), Data
transmitted to PROJECTOR is not recognised.
• In case of USER mode on PROJECTOR, a picture displayed might disappear accidentally and also
might come out of any status to the normal, when a Command, especially DATA WRITE COMMAND
is transmitted.
• In both cases of USER and SERVICEMAN mode, if PROJECTOR receives DATA WRITE
COMMAND such as SYSTEM SELECT COMMAND and ACTIVE MEMORY WRITE
COMMAND, PROJECTOR needs some more time to check its Data as explained bellow before
sending back the Return Data to CONTROLLER. It takes around 800 ms totally between transmission
of a Command from CONTROLLER and that of a Return Data from PROJECTOR.
• WhenSYSTEMSELECT COMMAND (CMD1=13hex) orACTIVEMEMORY WRITE COMMAND
(CMD1=32hex) is transmitted, its Data is checked by PROJECTOR firstly whether it is out of range
or not. In case of out of range of Data, the followings are implemented by PROJECTOR.
a) In case of SYSTEM SELECT COMMAND (CMD1=13hex)
- ‘NAK’ is sent back from PROJECTOR to CONTROLLER. It takes around 800 ms until
‘NAK’ is sent back.
b) In case of ACTIVE MEMORY COMMAND (CMD1=32hex)
- Data is replaced automatically into appropriate one as it is just within a range, and ‘NAK
(RANGE OVER / Data = 06hex)’ is transmitted to CONTROLLER. It takes also around
800 ms until ‘NAK’ is sent back.
- Range of Data for SYSTEM SELECT COMMAND is described on Protocol Table attached.
- Range of Data for ACTIVE MEMORY WRITE COMMAND is not available as Table, since its
Data is justified automatically as mentioned above.
- Range of Data for ACTIVE MEMORY WRITE COMMAND depends on the horizontal frequency
of a signal inputted, either a product model ( G70/D50 ) itself.
• After transmission of SIRCS DIRECT COMMAND (CMD1=16hex) and that of a Return Data
(CMD1=10hex) from PROJECTOR , CONTROLLER shall not send the next SIRCS DIRECT
COMMAND immediately. More than 180 ms is required for its interval.