EverFocus DVR-100H User Manual

Page 49

Advertising
background image

2-1. The format of message packet is as follows:

Length Byte (Prefix: 0x86, 0x87, or 0x88 ..... )
Receiver ID high byte
Receiver ID low byte
Opcode Byte
Data Byte1
Data Byte2
Data Byte3
.
.
Checksum Byte

2-2. Length Byte

This Length Byte is also a prefix. Bit7 must be 1.

EX:

0x87 ==> this packets has 7 bytes length. ( not included Length byte itself )

2-3. Receiver ID

1). Individual receiver ID

---------------------------------------------------------------------
Decimal

14bit binary value

Hbyte Lbyte

Receiver ID

(Digital Video Recorder)

-------

------------------- ------

------ ----------------------

0

0000000 0000000

00 00

ID = 0

1

0000000 0000001

00 01

ID = 1

2

0000000 0000010

00 02

ID = 2

....
126

0000000 1111110

00 7e

ID = 126

127

0000000 1111111

00 7f

ID = 127

128

0000001 0000000

01 00

ID = 128

129

0000001 0000001

01 01

ID = 129

255

0000001 1111111

01 7f

ID = 255

256

0000010 0000000

02 00

ID = 256

....
511

0000011 1111111

03 7f

ID = 511

....
16382

1111111 1111110

7f 7e

ID = 16382

---------------------------------------------------------------------

2). Broadcast ID

---------------------------------------------------------------------
Decimal

14bit binary value

Hbyte Lbyte Receiver ID (Digital Video Recorder)

-------

------------------- ------

------ ----------------------

16383

1111111 1111111

7f

7f all DVR connect to RS485

---------------------------------------------------------------------

43

Advertising