©NEC Display Solutions, Ltd. 2014-2020
10
2.1
Understanding command details
In this manual, commands and responses are expressed as follows.
20h 88h
<ID1>
<ID2>
0Ch
<DATA01>
-
<DATA12>
<CKS>
Command/response
A series of strings enclosed in a frame represents a command or response (in
hexadecimal notation).
Parameter
A character string in italic enclosed in brackets represents a parameter.
For information about the parameters that are common to the control commands
(ID1, ID2, CKS, LEN, ERR1, and ERR2), see "2.2 Parameters" (page 10). For
information about those parameters whose content varies from command to
command (DATA), see the description of the relevant command.
2.2
Parameters
The parameters that are used in the control commands are listed below.
Parameter name
Description
ID1
Control ID
The value of the "control ID" set for the projector is used.
ID2
Model code
This varies depending on the model in use.
CKS
Checksum
The checksum is calculated as follows.
①
Add all preceding bytes of data.
②
Use the value of the low-order one byte (eight bits) of the addition
result obtained in
①
as the checksum.
LEN
Data length
This indicates the data length of the data part (DATA??) following LEN (in
bytes).
DATA??
Variable length data
This varies depending on the character string stored.
ERR1
ERR2
Response error
The cause of an error is represented by a combination of error codes.
For information about error codes, see "2.4 Error code list" (page 12).
Example of checksum calculation
20h 81h 01h 60h 01h 00h
<CKS>
①
Add all the data preceding the checksum.
"20h + 81h + 01h + 60h + 01h + 00h = 103h"
②
Use the low-order one byte "03h" of the addition result obtained in
①
as the checksum.
