opc ua write to modbus

Author: BoBiene

modbushandler.js

@@ -43,35 +43,42 @@ var modbushandler = {
     ReadValue: function (name) {
         //console.log("read ", this.ValueMap);
         var val = this.ValueMap[name];
+        let statusCode;
         if (!val) {
-            return opcua.StatusCodes.BadDataUnavailable;
+            statusCode = opcua.StatusCodes.BadDataUnavailable;
         }
-        if (val.q != "good") {
-            return opcua.StatusCodes.BadConnectionRejected;//Bad;
+        if (val?.q != "good") {
+            switch (val?.q) {
+                case "BadNotConnected":
+                    statusCode = opcua.StatusCodes.BadNotConnected;
+                    break;
+                case "BadCommunicationError":
+                default:
+                    statusCode = opcua.StatusCodes.BadCommunicationError;
+                    break;
+
+            }
         }
-        return val.v;
+        return new opcua.DataValue({ "value": val?.v, "statusCode": statusCode, "sourceTimestamp": new Date() });
     },
-    WriteValue: function (type, address, variant) {
-        switch (type) {
-            case "holdingregister":
-                var value = parseInt(variant.value);
-                this.modbusclient.writeSingleRegister(address, value).then(function (resp) {
-
-                    // resp will look like { fc: 6, byteCount: 4, registerAddress: 13, registerValue: 42 } 
-                    console.log("Writing to holding register address: " + resp.registerAddress + " value: ", resp.registerValue);
-
-                }).fail(console.log);
-                break;
-            case "coils":
-                var value = ((variant.value) === 'true');
-                this.modbusclient.writeSingleCoil(address, value).then(function (resp) {
-
-                    // resp will look like { fc: 5, byteCount: 4, outputAddress: 5, outputValue: true } 
-                    console.log("Writing to coil address: " + resp.outputAddress + " value: " + resp.outputValue);
-
-                }).fail(console.log);
-                break;
+    WriteValue: async function (type, address, variant) {
+        try {
+            switch (type) {
+                case "holdingregister": {
+                    var value = parseInt(variant.value);
+                    let resp = await this.modbusclient.writeSingleRegister(address, value);
+                    return true;
+                }
+                case "coils": {
+                    var value = ((variant.value) === 'true');
+                    let resp = await this.modbusclient.writeSingleCoil(address, value);
+                    return true;
+                }
+            }
+        } catch (er) {
+            console.error('unable to write %s', address, er);
         }
+        return false;
     },
     CreateModbusDevice: function (host, port, unit) {
         this.socket = new net.Socket();
@@ -88,17 +95,17 @@ var modbushandler = {
         let recon = new Reconnect(this.socket, options);
         this.socket.connect(options);
 
-        console.log("Created a Modbus device on %s:%d %s",host,port,unit);
+        console.log("Created a Modbus device on %s:%d %s", host, port, unit);
         this.modbusclient = mclient;
         let connectionState = false;
         this.socket.on('error', () => {
             if (connectionState)
-                console.warn("Lost connection to Modbus device on %s:%d %s",host,port,unit);
+                console.warn("Lost connection to Modbus device on %s:%d %s", host, port, unit);
             connectionState = false;
         });
         this.socket.on('connect', () => {
             if (!connectionState) {
-                console.info("Connection established to Modbus device on %s:%d %s",host,port,unit);
+                console.info("Connection established to Modbus device on %s:%d %s", host, port, unit);
             }
             connectionState = true;
         });

server.js

@@ -74,7 +74,7 @@ function create_modbus_variables(server, modbushandler, rootname, register, type
     modbushandler.StartPoll(rootname, type, StartAddress, count, device.pollrate);
     const addressSpace = server.engine.addressSpace;
     const namespace = addressSpace.getOwnNamespace();
- 
+
     for (var i = 0; i < count; i++) {
         //console.log("creating variable: " + (address + count).toString());
         var node = function (register, type, address, i) {
@@ -84,12 +84,20 @@ function create_modbus_variables(server, modbushandler, rootname, register, type
                 minimumSamplingInterval: device.pollrate,
                 dataType: modbushandler.GetDataTypeString(type),
                 value: {
-                    get: function () {
+                    timestamped_get: function () {
                         return modbushandler.ReadValue(rootname + (StartAddress + i).toString());
                     },
-                    set: function (variant) {
-                        modbushandler.WriteValue(type, StartAddress + i, variant);
-                        return opcua.StatusCodes.Good;
+                    timestamped_set: function (dataValue, callback) {
+                        (async function () {
+                            try {
+                                if (await modbushandler.WriteValue(type, StartAddress + i, dataValue.value) == true)
+                                    callback(null, opcua.StatusCodes.Good);
+                                else
+                                    callback(null, opcua.StatusCodes.Bad);
+                            } catch (err) {
+                                callback(err, null);
+                            }
+                        })();
                     }
                 }
             }
@@ -130,7 +138,7 @@ function create_modbus_variables(server, modbushandler, rootname, register, type
             registerDeviceToUAServer(server, devicesnode, namespace, {
                 "modbushost": options.modbusHost,
                 "modbusport": options.modbusPort,
-                "pollrate" : options.modbusPollrate,
+                "pollrate": options.modbusPollrate,
                 "unit": options.modbusUnitId,
                 "onebased": !!options.modbusNotOnebased,
                 "deviceaddressspace": [