diff --git a/a8000_protocol b/a8000_protocol
index 6d52b54..e2eaf4c 160000
--- a/a8000_protocol
+++ b/a8000_protocol
@@ -1 +1 @@
-Subproject commit 6d52b54e3c528a0be076d120d033ecfeb1051ee0
+Subproject commit e2eaf4ce208aaa149127d2bf8fe41434fd63fd08
diff --git a/usrc/subboards/subboard90_optical_module/optical_module_v2.cpp b/usrc/subboards/subboard90_optical_module/optical_module_v2.cpp
index ea2605e..923eb35 100644
--- a/usrc/subboards/subboard90_optical_module/optical_module_v2.cpp
+++ b/usrc/subboards/subboard90_optical_module/optical_module_v2.cpp
@@ -62,8 +62,11 @@ void OpticalModuleV2::initialize(int32_t moduleid, hardware_config_t* hardwarecf
   m_t_amp_sw_io.setState(true);
   m_f_amp_sw_io.setState(true);
 
-  m_reg.t_pos_offset       = (4005 - 331);
-  m_reg.f_pos_offset       = (2860 - 331);
+  m_reg.t_pos_offset              = (4005 - 331);
+  m_reg.f_pos_offset              = (2860 - 331);
+  m_reg.t_reverse_scan_pos_offset = (2860 - 331) - 1200;
+  m_reg.f_reverse_scan_pos_offset = (2860 - 331) - 1200;
+
   m_reg.scan_step_interval = 1;
   m_reg.scan_pointnum      = 1200;
 
@@ -127,6 +130,9 @@ int32_t OpticalModuleV2::module_xxx_reg(int32_t param_id, bool read, int32_t& va
   switch (param_id) {
     PROCESS_REG(kreg_a8k_opt_t_pos_offset, REG_GET(m_reg.t_pos_offset), REG_SET(m_reg.t_pos_offset));
     PROCESS_REG(kreg_a8k_opt_f_pos_offset, REG_GET(m_reg.f_pos_offset), REG_SET(m_reg.f_pos_offset));
+    PROCESS_REG(kreg_a8k_opt_t_reverse_scan_pos_offset, REG_GET(m_reg.t_reverse_scan_pos_offset), REG_SET(m_reg.t_reverse_scan_pos_offset));
+    PROCESS_REG(kreg_a8k_opt_f_reverse_scan_pos_offset, REG_GET(m_reg.f_reverse_scan_pos_offset), REG_SET(m_reg.f_reverse_scan_pos_offset));
+
     PROCESS_REG(kreg_a8k_opt_scan_step_interval, REG_GET(m_reg.scan_step_interval), REG_SET(m_reg.scan_step_interval));
     PROCESS_REG(kreg_a8k_opt_scan_pointnum, REG_GET(m_reg.scan_pointnum), REG_SET(m_reg.scan_pointnum));
     default:
@@ -169,7 +175,7 @@ int32_t OpticalModuleV2::start_t_optical_scan(int32_t scanDirection, int32_t las
       scanStartPos = m_reg.t_pos_offset;
     } else {
       intervalStep = m_reg.scan_step_interval;
-      scanStartPos = m_reg.t_pos_offset - MAX_SCAN_POINT_NUM;
+      scanStartPos = m_reg.t_reverse_scan_pos_offset;
     }
 
     move_to_block(scanStartPos);
@@ -211,6 +217,10 @@ int32_t OpticalModuleV2::start_t_optical_scan(int32_t scanDirection, int32_t las
     m_t_laster_enable_io.setState(false);
     motor_release();
     _close_t_amp_n5v();
+
+    if (scanDirection < 0) {
+      reverse_capture_data();
+    }
   });
   return 0;
 
@@ -230,7 +240,7 @@ int32_t OpticalModuleV2::start_f_optical_scan(int32_t scanDirection, int32_t las
       scanStartPos = m_reg.f_pos_offset;
     } else {
       intervalStep = m_reg.scan_step_interval;
-      scanStartPos = m_reg.f_pos_offset - MAX_SCAN_POINT_NUM;
+      scanStartPos = m_reg.f_reverse_scan_pos_offset;
     }
 
     move_to_block(scanStartPos);
@@ -275,6 +285,9 @@ int32_t OpticalModuleV2::start_f_optical_scan(int32_t scanDirection, int32_t las
     }
     motor_release();
     a8000_optical_close_laser(kf_optical);
+    if (scanDirection < 0) {
+      reverse_capture_data();
+    }
   });
 
   // adc_capture_buf[0]
@@ -563,4 +576,20 @@ int32_t OpticalModuleV2::a8k_opt_v2_f_readVal(int32_t* lasteradc, int32_t* scana
   *lasteradc = adcval;
   ZLOGI(TAG, "a8k_opt_v2_f_readVal %d %d", *lasteradc, *scanadc);
   return 0;
-}
\ No newline at end of file
+}
+int32_t OpticalModuleV2::reverse_capture_data() {
+  // adc_capture_buf
+  // adc_capture_point_num
+  // 反向adc_capture_buf中的数据
+
+  for (int32_t i = 0; i < adc_capture_point_num / 2; i++) {
+    int32_t temp                               = adc_capture_buf[i];
+    adc_capture_buf[i]                         = adc_capture_buf[adc_capture_point_num - i];
+    adc_capture_buf[adc_capture_point_num - i] = temp;
+  }
+
+  // for (int32_t i = 0; i < adc_capture_point_num; i++) {
+  //   adc_capture_buf_tmp_buf[i] = adc_capture_buf[adc_capture_point_num - i];
+  // }
+  // memcpy(adc_capture_buf, adc_capture_buf_tmp_buf, adc_capture_point_num * sizeof(int16_t));
+}
diff --git a/usrc/subboards/subboard90_optical_module/optical_module_v2.hpp b/usrc/subboards/subboard90_optical_module/optical_module_v2.hpp
index 583542f..4a06d8b 100644
--- a/usrc/subboards/subboard90_optical_module/optical_module_v2.hpp
+++ b/usrc/subboards/subboard90_optical_module/optical_module_v2.hpp
@@ -42,6 +42,8 @@ class OpticalModuleV2 : public ZIModule, public ZIA8000OpticalModule {
   typedef struct {
     int32_t t_pos_offset;
     int32_t f_pos_offset;
+    int32_t t_reverse_scan_pos_offset;
+    int32_t f_reverse_scan_pos_offset;
     int32_t scan_step_interval;
     int32_t scan_pointnum;
   } reg_table_t;
@@ -78,7 +80,7 @@ class OpticalModuleV2 : public ZIModule, public ZIA8000OpticalModule {
 
   ZThread m_thread;
 
-  int16_t adc_capture_buf[4096] = {0};
+  int16_t adc_capture_buf[2000] = {0};
   int32_t adc_capture_point_num = 0;
 
   int32_t f_adc_cache[20];
@@ -159,31 +161,33 @@ class OpticalModuleV2 : public ZIModule, public ZIA8000OpticalModule {
   int32_t a8000_optical_set_scan_amp_gain(int32_t type, int32_t gain);
   int32_t a8000_optical_read_laster_adc_val(int32_t type, int32_t* adcval);
   int32_t a8000_optical_read_scanner_adc_val(int32_t type, int32_t* adcval);
+
+  int32_t reverse_capture_data();
 };
 }  // namespace iflytop
 
 /**
- * @brief 
- * 
- * 
- * 
- * 
+ * @brief
+ *
+ *
+ *
+ *
  * F光学:
  *    发射管增益0最大，255最小，最大和最小大概2倍关系
  *    接收管数值越大，放大倍数越大
- * 
+ *
  * T光学:
- *    
- * 
- * 
+ *
+ *
+ *
  * 光学步长:
  *  0.0127mm
  * 总扫描区长度
  *  15.24->1200步  (PS:板卡反应区长度15.90,但如果去掉底部纸板的黑色块，刚好15.24)
- * 
- * 
+ *
+ *
  * 1. 推杆电机将板夹推到49位置为板夹扫描位
  *        此时T光学电机起始步:4005 - 331
  *        此时F光学电机起始步:2860 - 331
- * 
+ *
  */
\ No newline at end of file