diff --git a/hgdriver/hgdev/hg_scanner_239.cpp b/hgdriver/hgdev/hg_scanner_239.cpp
index 3928b1a..d311b05 100644
--- a/hgdriver/hgdev/hg_scanner_239.cpp
+++ b/hgdriver/hgdev/hg_scanner_239.cpp
@@ -1696,7 +1696,25 @@ int hg_scanner_239::get_device_log(string &logpath)
 		return ret;
 	
 	str.resize(buffersize);
-	ret = io_->read_bulk(&str[0],&buffersize);
+	int block = buffersize,
+		total = buffersize,
+		index = 0;
+	
+	while (total > 0)
+	{
+		block = 512 * 1024;
+		if (total< block)
+		{
+			block = total;
+		}
+		ret = io_->read_bulk(&str[index], &block);
+		if (ret != SCANNER_ERR_OK)
+			return ret;
+
+		index += block;
+		total -= block;
+	}
+	
 	if (ret != SCANNER_ERR_OK)
 		return ret;