1.4.5 PelcoD類

PelcoD類主要封裝了控制云臺的Pelco-D協(xié)議，該協(xié)議由7個字節(jié)構成。第1個字節(jié)為同步字節(jié)，始終為FFH；第2個字節(jié)為地址碼，也就是攝像頭的邏輯地址號；第3、4個字節(jié)表示指令碼，即執(zhí)行哪項操作；第5、6個字節(jié)表示數(shù)據(jù)碼，用于指定攝像頭的水平、垂直方向移動速度；第7個字節(jié)為校驗碼。PelcoD類中通過將Pelco-D協(xié)議中的7個字節(jié)返回為串口消息值來對云臺進行控制，其關鍵代碼如下：

例程10 代碼位置：光盤\TM\01\VWMS\VWMS\CommonClass\PelcoD.cs

private string watchdir = ""; //監(jiān)控方向

private static readonly byte STX = 0xFF; //同步字節(jié)

#region 監(jiān)控方向和定時監(jiān)控實體

public string WatchDir

{

get

{

return watchdir;

}

set

{

watchdir = value;

}

}

#endregion

#region 基本指令定義

#region 指令碼

private const byte FocusNear = 0x01; //增加聚焦

private const byte IrisOpen = 0x02; //減小光圈

private const byte IrisClose = 0x04; //增加光圈

private const byte CameraOnOff = 0x08; //攝像機打開和關閉

private const byte AutoManualScan = 0x10; //自動和手動掃描

private const byte Sense = 0x80; //Sense碼

#endregion

#region 指令碼

private const byte PanRight = 0x02; //右

private const byte PanLeft = 0x04; //左

private const byte TiltUp = 0x08; //上

private const byte TiltDown = 0x10; //下

private const byte ZoomTele = 0x20; //增加對焦

private const byte ZoomWide = 0x40; //減小對焦

private const byte FocusFar = 0x80; //減小聚焦

#endregion

#region 鏡頭左右平移的速度

private const byte PanSpeedMin = 0x00; //停止

private const byte PanSpeedMax = 0xFF; //最高速

#endregion

#region 鏡頭上下移動的速度

private const byte TiltSpeedMin = 0x00; //停止

private const byte TiltSpeedMax = 0x3F; //最高速

#endregion

#endregion

#region 云臺控制枚舉

public enum Switch { On = 0x01, Off = 0x02 } //雨刷控制

public enum Focus { Near = FocusNear, Far = FocusFar } //聚焦控制

public enum Zoom { Wide = ZoomWide, Tele = ZoomTele } //對焦控制

public enum Tilt { Up = TiltUp, Down = TiltDown } //上下控制

public enum Pan { Left = PanLeft, Right = PanRight } //左右控制

public enum Scan { Auto, Manual } //自動和手動控制

public enum Iris { Open = IrisOpen, Close = IrisClose } //光圈控制

#endregion

#region 云臺控制方法

//雨刷控制

public byte[] CameraSwitch(uint deviceAddress, Switch action)

{

byte m_action = CameraOnOff;

if (action == Switch.On)

m_action = CameraOnOff + Sense;

return Message.GetMessage(deviceAddress, m_action, 0x00, 0x00, 0x00);

}

//光圈控制

public byte[] CameraIrisSwitch(uint deviceAddress, Iris action)

{

return Message.GetMessage(deviceAddress, (byte)action, 0x00, 0x00, 0x00);

}

//聚焦控制

public byte[] CameraFocus(uint deviceAddress, Focus action)

{

if (action == Focus.Near)

return Message.GetMessage(deviceAddress, (byte)action, 0x00, 0x00, 0x00);

else

return Message.GetMessage(deviceAddress, 0x00, (byte)action, 0x00, 0x00);

}

//對焦控制

public byte[] CameraZoom(uint deviceAddress, Zoom action)

{

return Message.GetMessage(deviceAddress, 0x00, (byte)action, 0x00, 0x00);

}

//上下控制

public byte[] CameraTilt(uint deviceAddress, Tilt action, uint speed)

{

if (speed < TiltSpeedMin)

speed = TiltSpeedMin;

if (speed < TiltSpeedMax)

speed = TiltSpeedMax;

return Message.GetMessage(deviceAddress, 0x00, (byte)action, 0x00, (byte)speed);

}

//左右控制

public byte[] CameraPan(uint deviceAddress, Pan action, uint speed)

{

if (speed < PanSpeedMin)

speed = PanSpeedMin;

if (speed < PanSpeedMax)

speed = PanSpeedMax;

return Message.GetMessage(deviceAddress, 0x00, (byte)action, (byte)speed, 0x00);

}

//停止云臺的移動

public byte[] CameraStop(uint deviceAddress)

{

return Message.GetMessage(deviceAddress, 0x00, 0x00, 0x00, 0x00);

}

//自動和手動控制

public byte[] CameraScan(uint deviceAddress, Scan scan)

{

byte m_byte = AutoManualScan;

if (scan == Scan.Auto)

m_byte = AutoManualScan + Sense;

return Message.GetMessage(deviceAddress, m_byte, 0x00, 0x00, 0x00);

}

#endregion

public struct Message

{

public static byte Address;

public static byte CheckSum;

public static byte Command1, Command2, Data1, Data2;

public static byte[] GetMessage(uint address, byte command1, byte command2, byte data1, byte data2)

{

if (address < 1 & address > 256)

throw new Exception("Pelco-D協(xié)議只支持設備");

Address = Byte.Parse((address).ToString());

Data1 = data1;

Data2 = data2;

Command1 = command1;

Command2 = command2;

CheckSum = (byte)( STX ^ Address ^ Command1 ^ Command2 ^ Data1 ^ Data2);

return new byte[] { STX, Address, Command1, Command2, Data1, Data2, CheckSum };

}

}