diff --git a/modules/opcua/include/rmvl/opcua/variable.hpp b/modules/opcua/include/rmvl/opcua/variable.hpp
index f2fd8f4..8c88550 100644
--- a/modules/opcua/include/rmvl/opcua/variable.hpp
+++ b/modules/opcua/include/rmvl/opcua/variable.hpp
@@ -166,7 +166,7 @@ class RMVL_EXPORTS_W Variable final
      * @param[in] str 字符串
      */
     template <std::size_t N>
-    Variable(const char (&str)[N]) : Variable(std::string(str, N)) {}
+    Variable(const char (&str)[N]) : Variable(std::string(str)) {}
 
     /**
      * @brief 列表构造
@@ -367,8 +367,8 @@ struct RMVL_EXPORTS_W_AG DataSourceVariable
     RMVL_W_RW std::string display_name{};
     //! 变量的描述
     RMVL_W_RW std::string description{};
-    //! 访问性
-    RMVL_W_RW uint8_t access_level{};
+    //! 访问性，默认为只读
+    RMVL_W_RW uint8_t access_level{1U};
 
     /**
      * @brief 数据源 Read 回调函数
diff --git a/modules/opcua/test/test_opcua_client.cpp b/modules/opcua/test/test_opcua_client.cpp
index 12c6041..df836f7 100644
--- a/modules/opcua/test/test_opcua_client.cpp
+++ b/modules/opcua/test/test_opcua_client.cpp
@@ -198,11 +198,13 @@ TEST(OPC_UA_ClientTest, event_monitor)
     srv.addEventTypeNode(etype);
     rm::Client cli("opc.tcp://127.0.0.1:5010");
 
-    std::string source_name;
+    std::string source_name{};
+    std::string messgae{};
     int aaa{};
-    cli.monitor({"SourceName", "aaa"}, [&](rm::ClientView, const rm::Variables &fields) {
-        source_name = fields[0].cast<std::string>();
-        aaa = fields[1];
+    cli.monitor({"Message", "SourceName", "aaa"}, [&](rm::ClientView, const rm::Variables &fields) {
+        messgae = fields[0].cast<std::string>();
+        source_name = fields[1].cast<std::string>();
+        aaa = fields[2];
     });
     // 触发事件
     auto event = rm::Event::makeFrom(etype);