diff --git a/docs/G439.txt b/docs/G439.txt
index 2f1d00c..a13a15a 100644
--- a/docs/G439.txt
+++ b/docs/G439.txt
@@ -386,7 +386,11 @@
 		"cur": 0.000000,
 		"default": 0.000000,
 		"size": 4,
-		"range": [0.000000, 0.000000, 0.000000],
+		"range": {
+			"min": 0.000000,
+			"max": 210.000000,
+			"step": 21.000000
+		},
 		"depend_and": ["is-custom-area==true"]
 	},
 	"br-x": {
@@ -401,10 +405,14 @@
 		"title": "扫描区域右侧（mm）",
 		"desc": "自定义扫描区域右下角x坐标",
 		"type": "float",
-		"cur": 0.000000,
-		"default": 0.000000,
+		"cur": 210.000000,
+		"default": 210.000000,
 		"size": 4,
-		"range": [0.000000, 0.000000, 0.000000],
+		"range": {
+			"min": 0.000000,
+			"max": 210.000000,
+			"step": 21.000000
+		},
 		"depend_and": ["is-custom-area==true"]
 	},
 	"tl-y": {
@@ -422,7 +430,11 @@
 		"cur": 0.000000,
 		"default": 0.000000,
 		"size": 4,
-		"range": [29.700000, 0.000000, 0.000000],
+		"range": {
+			"min": 0.000000,
+			"max": 297.000000,
+			"step": 29.700000
+		},
 		"depend_and": ["is-custom-area==true"]
 	},
 	"br-y": {
@@ -437,10 +449,14 @@
 		"title": "扫描区域下侧（mm）",
 		"desc": "自定义扫描区域右下角y坐标",
 		"type": "float",
-		"cur": 0.000000,
-		"default": 0.000000,
+		"cur": 297.000000,
+		"default": 297.000000,
 		"size": 4,
-		"range": [29.700000, 0.000000, 0.000000],
+		"range": {
+			"min": 0.000000,
+			"max": 297.000000,
+			"step": 29.700000
+		},
 		"depend_and": ["is-custom-area==true"]
 	},
 	"is-size-check": {