The range and usage of parameters such as speed, direction, and zoom in the Pelco-D protocol

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1. Direction control (left/right/up/down)

• Control method: The direction is activated through the binary bit (BIT) of thecommand 1 (3rd byte) in the telegram.The direction of the binary bit (BIT) being turned on.
• Value range: Onlyis either on (1) or off (0), with no intermediate values. For example:
• Turn left:0x04(Binary0000 0100, BIT3=1)
• Right Turn:0x02(Binary0000 0010, BIT2=1)
• Upward Rotation:0x08(Binary0000 1000, BIT4=1)
• Downward Rotation:0x10(Binary0001 0000, BIT5=1)
• Speed Control: Determined byData 1 (5th byte) And Data 2 (6th byte):
• Horizontal speed (left/right): Data 1 (5th byte), range from0x00(stop) to0xFF(fastest).
• Vertical speed (up/down): Data 2 (6th byte), range as above.
• Note: The specific speed value is determined by the camera, for example:
  • 0x00= stop
  • 0x20= slow
  • 0xFF= Fastest

Example: Instruct the camera torotate left at medium speed, and rotate up slowly:

FF 01 0C 00 3F 20 XX

• . Command 1 =0x0C(binary0000 1100, left rotation0x04+ up rotation0x08)
• ). Data 1 =0x3F(horizontal speed at medium speed)
• . Data 2 =0x20(Vertical speed slow)

2. Zoom (Zoom in/Zoom out)

• Control method: Enable zoom by the binary bit ofcommand 2 (4th byte).
• Value range: Onlyis on (1) or off (0), with no speed value. For example:
• Zoom in:0x20(binary)0010 0000, BIT6=1)
• Zoom-out:0x40(binary0100 0000, BIT7=1)
• Speed control: Zoom speed is usually preset by the camera hardware and cannot be adjusted through the Pelco-D protocol (some cameras may support special commands).

Example: Instruct the camera tocontinuously zoom in:

FF 01 00 20 00 00 XX

• with command 2 =0x20(zoom in)

3. Focus (sharp/blurry)

• Control mode: Focus is enabled through the binary bit ofCommand 2 (4th byte).
• Value range: Onlycan be turned on (1) or off (0):
• . Focus far (more clear):0x80(binary1000 0000, BIT8=1)
• . Focus near (more blurry):0x01(binary0000 0001, BIT1=1)

Example: Adjust the camerato achieve clearer:

FF 01 00 80 00 00 XX

• Command 2 =0x80(Focus far)

4. Other functions (preset positions, scanning, etc.)

• Preset position call: Implemented through the combination ofCommand 2 and Data 1/Data 2.
• Call preset bit 5: Data 1 =0x00(high bit), Data 2 =0x05(low bit), Command 2 =0x07.
• Auto scan: Command 2 =0x90(enable auto scan).

Summary table

Notes

1. Simultaneous Control of Multiple Functions: This can be achieved by combining binary bits.
   For example: Left Turn + Up Turn =0x04 + 0x08 = 0x0C(Command 1).
2. Stop all actions: Send messages with all control bits set to0x00.
   Example:FF 01 00 00 00 00 XX.
3. Device differences: Different cameras may interpret speed values differently. It is recommended to refer to the device manual.