Pelco D message structure

Pelco D message structure

Byte 0	Byte 1	Byte 2	Byte 3	Byte 4	Byte 5	Byte 6
Synch Byte	Address	Command 1	Command 2	Data 1	Data 2	Check Sum

Byte 0 The synchronization byte is always $FF.

	Bit 7	Bit 6	Bit 5	Bit 4	Bit 3	Bit 2	Bit 1	Bit 0
Cmd 1	Sense	0	0	Auto / Manual Scan	Camera On / Off	Iris Close	Iris Open	Focus Near
Cmd 2	Focus Far	Zoom Wide	Zoom Tele	Down	Up	Left	Right	0
Data 1	Pan Speed $00 to $3F and $40 for Turbo
Data 2	Tilt Speed $00 to $3F

Byte 6: checksum. The check sum is the sum of bytes (excluding the synchronization byte) modulo 256.

The sense bit (command 1 bit 7) indicates the meaning of bits 4 and 3.  If the sense bit is on, and bits 4 and

3 are on, the command will enable auto-scan and turn the camera on.  If the sense bit is off and bits 4 and 3

are on the command will enable manual scan and turn the camera off.  Of course, if either bit 4 or bit 3 are

off then no action will be taken for those features.

The reserved bits (6 and 5) should be set to 0.

EXTENDED COMMANDS

Command	Word 3	Word 4	Word 5	Word 6
Set Preset	00	03	00	01 to 20
Clear Preset	00	05	00	01 to 20
Go To Preset	00	07	00	01 to 20
Flip (180° about)	00	07	00	21
Go To Zero Pan	00	07	00	22
Set Auxiliary	00	09	00	01 to 08
Clear Auxiliary	00	0B	00	01 to 08
Remote Reset	00	0F	00	00
Set Zone Start	00	11	00	01 to 08
Set Zone End	00	13	00	01 to 08
Write Char. To Screen	00	15	X Position 00 to 28	ASCII Value
Clear Screen	00	17	00	00
Alarm Acknowledge	00	19	00	Alarm No.
Zone Scan On	00	1B	00	00
Zone Scan Off	00	1D	00	00
Set Pattern Start	00	1F	00	00
Set Pattern Stop	00	21	00	00
Run Pattern	00	23	00	00
Set Zoom Speed	00	25	00	00 to 03
Set Focus Speed	00	27	00	00 to 03