diff --git a/src/slic3r/GUI/DeviceCore/DevFilaSystem.cpp b/src/slic3r/GUI/DeviceCore/DevFilaSystem.cpp
index fdeec610d5..ab5c61d26a 100644
--- a/src/slic3r/GUI/DeviceCore/DevFilaSystem.cpp
+++ b/src/slic3r/GUI/DeviceCore/DevFilaSystem.cpp
@@ -38,8 +38,6 @@ void DevAmsTray::UpdateColorFromStr(const std::string& color)
     }
 }
 
-wxColour DevAmsTray::get_color() { return decode_color(color); }
-
 void DevAmsTray::reset()
 {
     tag_uid             = "";
@@ -66,7 +64,7 @@ void DevAmsTray::reset()
 }
 
 
-bool DevAmsTray::is_tray_info_ready()
+bool DevAmsTray::is_tray_info_ready() const
 {
     if (color.empty()) return false;
     if (type.empty()) return false;
@@ -74,13 +72,13 @@ bool DevAmsTray::is_tray_info_ready()
     return true;
 }
 
-bool DevAmsTray::is_unset_third_filament()
+bool DevAmsTray::is_unset_third_filament() const
 {
     if (this->is_bbl) return false;
     return (color.empty() || type.empty());
 }
 
-std::string DevAmsTray::get_display_filament_type()
+std::string DevAmsTray::get_display_filament_type() const
 {
     if (type == "PLA-S") return "Sup.PLA";
     if (type == "PA-S") return "Sup.PA";
diff --git a/src/slic3r/GUI/DeviceCore/DevFilaSystem.h b/src/slic3r/GUI/DeviceCore/DevFilaSystem.h
index 567bc6cf2b..8b05e022d8 100644
--- a/src/slic3r/GUI/DeviceCore/DevFilaSystem.h
+++ b/src/slic3r/GUI/DeviceCore/DevFilaSystem.h
@@ -24,14 +24,6 @@ public:
         id = tray_id;
     }
 
-    static wxColour decode_color(const std::string& color);
-
-    bool operator==(DevAmsTray const& o) const
-    {
-        return id == o.id && type == o.type && filament_setting_id == o.filament_setting_id && color == o.color;
-    }
-    bool operator!=(DevAmsTray const& o) const { return !operator==(o); }
-
     std::string              id;
     std::string              tag_uid;             // tag_uid
     std::string              setting_id;          // tray_info_idx
@@ -61,16 +53,30 @@ public:
     int             hold_count = 0;
     int             remain = 0;         // filament remain: 0 ~ 100
 
-    void set_hold_count() { hold_count = HOLD_COUNT_MAX; }
-    void UpdateColorFromStr(const std::string& color);
-    wxColour get_color();
+public:
+    // operators
+    bool operator==(DevAmsTray const& o) const
+    {
+        return id == o.id && type == o.type && filament_setting_id == o.filament_setting_id && color == o.color;
+    }
+    bool operator!=(DevAmsTray const& o) const { return !operator==(o); }
 
+    // setters
     void reset();
+    void UpdateColorFromStr(const std::string& color);
+    void set_hold_count() { hold_count = HOLD_COUNT_MAX; }
 
-    bool is_tray_info_ready();
-    bool is_unset_third_filament();
-    std::string get_display_filament_type();
+    // getter
+    bool is_tray_info_ready() const;
+    bool is_unset_third_filament() const;
+
+    wxColour    get_color()  const { return decode_color(color); };
+
+    std::string get_display_filament_type() const;
     std::string get_filament_type();
+
+    // static
+    static wxColour decode_color(const std::string& color);
 };
 
 class DevAms
diff --git a/src/slic3r/GUI/DeviceCore/DevMapping.cpp b/src/slic3r/GUI/DeviceCore/DevMapping.cpp
index 52d324c646..e655f12db7 100644
--- a/src/slic3r/GUI/DeviceCore/DevMapping.cpp
+++ b/src/slic3r/GUI/DeviceCore/DevMapping.cpp
@@ -72,7 +72,7 @@ namespace Slic3r
         bool  is_type_match = true;
     };
 
-    static void _parse_tray_info(int ams_id, int slot_id, DevAmsTray tray, FilamentInfo& result)
+    static void _parse_tray_info(int ams_id, int slot_id, DevAms::AmsType type, DevAmsTray tray, FilamentInfo& result)
     {
         result.color = tray.color;
         result.type = tray.get_filament_type();
@@ -91,7 +91,14 @@ namespace Slic3r
         }
         else
         {
-            result.id = ams_id * 4 + slot_id;
+            if (type == DevAms::N3S)
+            {
+                result.id = ams_id + slot_id;
+            }
+            else
+            {
+                result.id = ams_id * 4 + slot_id;
+            }
         }
     }
 
@@ -138,7 +145,7 @@ namespace Slic3r
                 FilamentInfo info;
                 if (tray->second->is_tray_info_ready())
                 {
-                    _parse_tray_info(ams_id, tray_id, *(tray->second), info);
+                    _parse_tray_info(ams_id, tray_id, ams_type, *(tray->second), info);
                 }
 
                 //first: left,nozzle=1,map=1   second: right,nozzle=0,map=2
@@ -179,7 +186,7 @@ namespace Slic3r
                         }
                     }
                     FilamentInfo info;
-                    _parse_tray_info(atoi(tray.id.c_str()), 0, tray, info);
+                    _parse_tray_info(atoi(tray.id.c_str()), 0, DevAms::DUMMY, tray, info);
                     tray_filaments.emplace(std::make_pair(info.tray_id, info));
                 }
             }