diff --git a/sl2-100/pd.py b/sl2-100/pd.py
index 570b612..94d6c6a 100644
--- a/sl2-100/pd.py
+++ b/sl2-100/pd.py
@@ -99,6 +99,7 @@ class Decoder(srd.Decoder):
         self.yv_cnt = 0        #y坐标校验累积的数据位个数
         self.yv_first = 0      #y坐标校验起始位置
         self.state = 'HEADER'  #当前处理的字段
+        self.state2 = 'FIND START'  #当前处理的字段
         self.data = 0          #存放坐标值数据
         self.highpin = 0       #当前采样宽度(78.125ns)内高电平数量
         self.lowpin = 0        #当前采样宽度(78.125ns)内低电平数量
@@ -126,14 +127,17 @@ class Decoder(srd.Decoder):
         if self.state == 'HEADER':
             self.header_str += str(bit)
             self.head_cnt = self.head_cnt+1
-            if self.head_cnt == 8:
+            if self.head_cnt == 6:
                 self.put(self.header_first, es, self.out_ann,[2, ['HEADER_x:' + self.header_str]])
                 self.state = 'xpos'
                 self.xpos_first = es
                 self.xpos_cnt = 0    #当前坐标 位数归零,准备累积
                 self.data = 0        #当前坐标值归零,准备开始累积
         elif self.state == 'xpos':
-            self.data = (bit << self.xpos_cnt) | self.data
+            if self.xpos_cnt == 19:
+                self.data = ((not bit) << self.xpos_cnt) | self.data
+            else:
+                self.data = (bit << self.xpos_cnt) | self.data
             self.xpos_cnt = self.xpos_cnt+1
             if self.xpos_cnt == 20:
                 self.put(self.xpos_first, es, self.out_ann,[3, ['X坐标:' + ': 0x%x' % self.data + ' = %d' % self.data]])
@@ -162,7 +166,10 @@ class Decoder(srd.Decoder):
                 self.ypos_cnt = 0    #当前坐标 位数归零,准备累积
                 self.data = 0        #当前坐标值归零,准备开始累积
         elif self.state == 'ypos':
-            self.data = (bit << self.ypos_cnt) | self.data
+            if self.ypos_cnt == 19:
+                self.data = ((not bit) << self.ypos_cnt) | self.data
+            else:
+                self.data = (bit << self.ypos_cnt) | self.data
             self.ypos_cnt = self.ypos_cnt+1
             if self.ypos_cnt == 20:
                 self.put(self.ypos_first, es, self.out_ann,[7, ['y坐标:' + ': 0x%x' % self.data + ' = %d' % self.data]])
@@ -178,6 +185,7 @@ class Decoder(srd.Decoder):
             if self.yv_cnt == 4:
                 self.put(self.yv_first, es, self.out_ann,[9, ['y校验:' + self.yv_str]])
                 self.state = 'HEADER'
+                self.state2 = 'FIND START'
                 self.header_first = es
                 self.head_cnt = 0
                 self.header_str = ""
@@ -223,18 +231,42 @@ class Decoder(srd.Decoder):
         self.lowpin = 0     #当前采样宽度(78.125ns)内低电平数量
 
         while True:
-            (pin,) = self.wait({0:'n'})
-            #当前已经累积的采样宽度
-            total_width = self.samplenum - self.oldsamplenum
-            if pin==1:
-                self.highpin += 1     #当前采样宽度内高电平数量加1
-            else:
-                self.lowpin += 1       #当前采样宽度内低电平数量加1
-            if total_width>=self.bit_width :         #累积采样宽度接近设置的采样次数
-                self.oldsamplenum = self.oldsamplenum+self.bit_width #当前采样结束作为下一采样的开始
-                self.manchester_decode(1 if self.highpin > self.lowpin else 0)
-                self.highpin = 0    #当前采样宽度(78.125ns)内高电平数量
-                self.lowpin = 0     #当前采样宽度(78.125ns)内低电平数量
+            if self.state2 == 'FIND START':                
+                #self.file.write('FIND START'+ '\n')
+                self.wait({0: 'l'})
+                self.oldsamplenum = self.samplenum
+                self.state2 = 'FIND START2'
+            if self.state2 == 'FIND START2':                
+                #self.file.write('FIND START2'+ '\n')
+                self.wait({0: 'r'})
+                start_width = self.samplenum - self.oldsamplenum                
+                self.oldsamplenum = self.samplenum
+                if start_width >= self.bit_width*2.2:
+                    self.state2 = 'FIND START3'
+                else:
+                    self.state2 = 'FIND START'
+            if self.state2 == 'FIND START3':                
+                #self.file.write('FIND START3'+ '\n')
+                (pin,) = self.wait({0:'n'})
+                #当前已经累积的采样宽度
+                total_width = self.samplenum - self.oldsamplenum
+                if total_width>=self.bit_width :         #累积采样宽度接近设置的采样次数
+                    self.state2 = 'FIND DATA'
+                    self.oldsamplenum = self.samplenum
+            if self.state2 == 'FIND DATA':                  
+                #self.file.write('FIND DATA'+ '\n')
+                (pin,) = self.wait({0:'n'})
+                #当前已经累积的采样宽度
+                total_width = self.samplenum - self.oldsamplenum
+                if pin==1:
+                    self.highpin += 1     #当前采样宽度内高电平数量加1
+                else:
+                    self.lowpin += 1       #当前采样宽度内低电平数量加1
+                if total_width>=self.bit_width :         #累积采样宽度接近设置的采样次数
+                    self.oldsamplenum = self.oldsamplenum+self.bit_width #当前采样结束作为下一采样的开始
+                    self.manchester_decode(1 if self.highpin > self.lowpin else 0)
+                    self.highpin = 0    #当前采样宽度(78.125ns)内高电平数量
+                    self.lowpin = 0     #当前采样宽度(78.125ns)内低电平数量
     # self.wait()可带参数，也可以不带参数，不带参数时将返回每个采样数据
     # 参数{0:'r'}， 0表示匹配channels第１项绑定的通道，'r'表示查找向上边沿
     # wait函数可传多个条件，与条件:{0:'f',１:'r'},　或条件：[{0:'f'},{１:'r'}]