Sony FWD-42PV1A Protocol Manual page 3

3. Communication Data Format
(a)Control message
Item
№
1 Header
Category
2
Function
3
Data1（Length）
4
5 Data2（Data1）
:
:
:
:
DataX
X
X+1
Check Sum
* Check Sum: The total from №1 to №X, when value exceeds 255, 1byte of data is confirmed the bottom.
* When sending controls in sequence, keep interval of more than 500ms between the commands.
* When sending an enquiry right after sending the control of a same command, also keep interval of more than 5
between the commands.
(b)Enquiry message
№ Item
Header
1
Category
2
Function
3
4 Data1
Data2
5
6
Check Sum
* Check Sum: The total from №1 to №5, when value exceeds 255, 1byte of data is confirmed the bottom.
(c)Answer message
(1)Control answer
№ Item
Header
1
Answer*
2
3
Check Sum
* 0x00: Completed
0x01: Limit Over
0x02: Limit Under
0x03: Command Canceled The packet was received normally, but the command was cancelled because the
* Check Sum: The total from №1 to №2, when value exceeds 255, 1byte of data is confirmed the bottom.
(2)Enquiry answer (Complete)
№ Item
Header
1
Answer
2
Return Data Size
3
4 Return Data1
:
:
:
:
X
Return DataX
Check Sum
X+1
* 0x00: Completed
* Return Data returns the read value.
* Check Sum: The total from №1 to №X, when value exceeds 255, 1byte of data is confirmed the bottom.
Value
0x8C: Control
0xXX
0xXX
0xXX
0xXX
0xXX
0xXX
0xXX
0xXX
Value
0x83: Enquiry
0xXX
0xXX
0xFF
0xFF
0xXX
Value
0x70: Answer
0x00: Completed
0x01: Limit Over
0x02: Limit Under
0x03: Command Canceled
0xXX
Normal response.
The packet was received normally, but the data value was over the upper limit.
Forcedly the monitor adjusted the data to maximum value.
The packet was received normally, but the data value was under the lower limit.
Forcedly the monitor adjusted the data to minimum value.
function was not in adjustable mode, such as "--" a function displayed as in user
menu.
Value
0x70: Answer
0x00: Completed
0xXX
0xXX
0xXX
0xXX
0xXX
0xXX
Normal response.