diff --git a/sane/s2t_api.h b/sane/s2t_api.h
index 8ee7545..d1eff00 100644
--- a/sane/s2t_api.h
+++ b/sane/s2t_api.h
@@ -158,6 +158,7 @@ struct __declspec(novtable) ISaneInvoker : public IRef
 	COM_API_DECLARE(bool, get_first_image_header(SANE_Parameters* header, size_t* bytes = NULL, int *dpi = NULL));
 	COM_API_DECLARE(bool, is_online(void));
 	COM_API_DECLARE(bool, is_paper_on(void));
+	COM_API_DECLARE(int, last_error(void));
 
 	// Function:	获取配置项信息
 	//
diff --git a/sane/scanner.cpp b/sane/scanner.cpp
index e7ebfff..29caaa2 100644
--- a/sane/scanner.cpp
+++ b/sane/scanner.cpp
@@ -2420,6 +2420,11 @@ COM_API_IMPLEMENT(scanner, bool, is_paper_on(void))
 	else
 		return false;
 }
+COM_API_IMPLEMENT(scanner, int, last_error(void))
+{
+	return err_;
+}
+
 COM_API_IMPLEMENT(scanner, bool, get_option_info(int sn, value_type* type, value_limit* limit, int* bytes))
 {
 	EXAPIPOS	ex = find_ex_api(sn);
@@ -2936,10 +2941,6 @@ int scanner::handle_device_event(int ev_code, void* data, unsigned int* len)
 
 	return 0;
 }
-int scanner::last_error(void)
-{
-	return err_;
-}
 
 
 
diff --git a/sane/scanner.h b/sane/scanner.h
index f6df115..6364d80 100644
--- a/sane/scanner.h
+++ b/sane/scanner.h
@@ -201,6 +201,7 @@ public:
 	COM_API_OVERRIDE(bool, get_first_image_header(SANE_Parameters* header, size_t* bytes = NULL, int* dpi = NULL));
 	COM_API_OVERRIDE(bool, is_online(void));
 	COM_API_OVERRIDE(bool, is_paper_on(void));
+	COM_API_OVERRIDE(int, last_error(void));
 	COM_API_OVERRIDE(bool, get_option_info(int sn, value_type* type, value_limit* limit, int* bytes));
 	COM_API_OVERRIDE(bool, get_value(int sn, set_opt_value, void* param));
 	COM_API_OVERRIDE(int, set_value(int sn, void* val));
@@ -325,5 +326,4 @@ public:
 	// methods:
 public:
 	int handle_device_event(int ev_code, void* data, unsigned int* len);
-	int last_error(void);
 };
\ No newline at end of file
diff --git a/twain/twain/huagaods.cpp b/twain/twain/huagaods.cpp
index a5b9855..5e447da 100644
--- a/twain/twain/huagaods.cpp
+++ b/twain/twain/huagaods.cpp
@@ -937,8 +937,14 @@ Twpp::ConditionCode huagao_ds::condition_code_from_hg_error(int hgerr)
 		return Twpp::ConditionCode::NoMedia;
 	if (hgerr == SCANNER_ERR_OPENED_BY_OTHER_PROCESS)
 		return Twpp::ConditionCode::MaxConnections;
+	if(hgerr == SCANNER_ERR_INSUFFICIENT_MEMORY)
+		return Twpp::ConditionCode::LowMemory;
+	if(hgerr == SCANNER_ERR_DEVICE_NOT_FOUND)
+		return Twpp::ConditionCode::NoDs;
 
-	return (Twpp::ConditionCode)((int)Twpp::ConditionCode::CustomBase + hgerr);
+	return ConditionCode::Bummer;
+
+	// return (Twpp::ConditionCode)((int)Twpp::ConditionCode::CustomBase + hgerr);
 }
 
 Result huagao_ds::capabilityGet(const Identity& origin, Capability& data) 
@@ -1286,7 +1292,7 @@ Result huagao_ds::imageLayoutGet(const Identity&, ImageLayout& data)
 	if (!scanner_.get())
 		return seqError();
 	else if(get_scanned_image_count(-1) == 0)
-		return { ReturnCode::XferDone, ConditionCode::Success };
+		return { ReturnCode::Failure, condition_code_from_hg_error(scanner_->last_error()) };
 
 	int res = 200;
 
@@ -1328,7 +1334,7 @@ Result huagao_ds::imageMemXferGet(const Identity& origin, ImageMemXfer& data)
 		//	return seqError();
 		//}
 
-		return { ReturnCode::XferDone, ConditionCode::Success };
+		return { ReturnCode::Failure, condition_code_from_hg_error(scanner_->last_error()) };
 	}
 
 	IScanImg		*img = pending_xfer_.img ? pending_xfer_.img : scanner_->take_first_image(TWAIN_XFER_Memory);
@@ -1404,7 +1410,7 @@ Result huagao_ds::imageNativeXferGet(const Identity& id, ImageNativeXfer& data)
 	if (!scanner_.get())
 		return seqError();
 	else if(get_scanned_image_count(-1) == 0)
-		return { ReturnCode::XferDone, ConditionCode::Success };
+		return { ReturnCode::Failure, condition_code_from_hg_error(scanner_->last_error()) };
 
 	IScanImg* img = scanner_->take_first_image(TWAIN_XFER_Native);
 
@@ -1445,7 +1451,7 @@ Twpp::Result huagao_ds::imageFileXferGet(const Twpp::Identity& origin)
 	if (!scanner_.get())
 		return seqError();
 	else if(get_scanned_image_count(-1) == 0)
-		return { ReturnCode::XferDone, ConditionCode::Success };
+		return { ReturnCode::Failure, condition_code_from_hg_error(scanner_->last_error()) };
 
 	IScanImg* img = scanner_->take_first_image(TWAIN_XFER_File); 
 	Twpp::Result	ret = seqError();