fixing sample_server, add minimumSamplingInterval #1133

documentation/sample_server.js

@@ -1,3 +1,4 @@
+const os = require("os");
 const { OPCUAServer, Variant, DataType, StatusCodes } = require("node-opcua");
 
 
@@ -27,42 +28,32 @@ const { OPCUAServer, Variant, DataType, StatusCodes } = require("node-opcua");
 
     // add some variables
     // add a variable named MyVariable1 to the newly created folder "MyDevice"
-    let variable1 = 1;
 
-    // emulate variable1 changing every 500 ms
-    setInterval(() => { variable1 += 1; }, 500);
 
-    namespace.addVariable({
+    const variable1 = namespace.addVariable({
         componentOf: device,
         browseName: "MyVariable1",
         dataType: "Double",
-        value: {
-            get: () => new Variant({ dataType: DataType.Double, value: variable1 })
-        }
+        minimumSamplingInterval: 100,
     });
 
+    let counter = 0;
+    // emulate variable1 changing every 500 ms
+    const timerId = setInterval(() => { counter += 1; variable1.setValueFromSource({ dataType: DataType.Double, value: counter }) }, 500);
+
+    addressSpace.registerShutdownTask(() => { clearInterval(timerId); });
+
     // add a variable named MyVariable2 to the newly created folder "MyDevice"
-    let variable2 = 10.0;
 
     namespace.addVariable({
 
         componentOf: device,
-
         nodeId: "ns=1;b=1020FFAA", // some opaque NodeId in namespace 4
-
         browseName: "MyVariable2",
-
         dataType: "Double",
-
-        value: {
-            get: () => new Variant({ dataType: DataType.Double, value: variable2 }),
-            set: (variant) => {
-                variable2 = parseFloat(variant.value);
-                return StatusCodes.Good;
-            }
-        }
+        minimumSamplingInterval: 0, // this variable will be event driven
     });
-    const os = require("os");
+
     /**
      * returns the percentage of free memory on the running machine
      * @return {double}
@@ -79,16 +70,20 @@ const { OPCUAServer, Variant, DataType, StatusCodes } = require("node-opcua");
         nodeId: "s=free_memory", // a string nodeID
         browseName: "FreeMemory",
         dataType: "Double",
+        minimumSamplingInterval: 1234,
         value: {
             get: () => new Variant({ dataType: DataType.Double, value: available_memory() })
         }
     });
 
-    server.start(function() {
-        console.log("Server is now listening ... ( press CTRL+C to stop)");
-        console.log("port ", server.endpoints[0].port);
-        const endpointUrl = server.endpoints[0].endpointDescriptions()[0].endpointUrl;
-        console.log(" the primary server endpoint url is ", endpointUrl);
+    await server.start();
+    console.log("Server is now listening ... ( press CTRL+C to stop)");
+    console.log("port ", server.endpoints[0].port);
+    console.log(" the primary server endpoint url is ", server.getEndpointUrl());
+
+    process.once("SIGINT", async () => {
+        console.log("shuting down");
+        await server.shutdown();
     });
 
 })();