# How to define Data Type STRING for opcua iiot flex server node

**URL:** <https://discourse.nodered.org/t/how-to-define-data-type-string-for-opcua-iiot-flex-server-node/74503>\
**Category:** General\
**Created:** [31 January 2023 17:42 UTC](https://discourse.nodered.org/t/how-to-define-data-type-string-for-opcua-iiot-flex-server-node/74503 "2023-01-31T17:42:54Z")\
**Posts on this page:** 6\
**Page:** 1

<div class="post-metadata">

**Author:** ![saraltech](https://avatars.discourse-cdn.com/v4/letter/s/71e660/32.png) [@saraltech](https://discourse.nodered.org/u/saraltech)\
**Post date:** [31 January 2023 17:42 UTC](https://discourse.nodered.org/t/how-to-define-data-type-string-for-opcua-iiot-flex-server-node/74503/1 "2023-01-31T17:42:54Z")

</div>

Dear Friends,  
I am trying to create opc ua server using from "node-red-contrib-iiot-opcua".  
I am able to get it working with data type as double. definition as shown below is working perfect:  
const gpioDI1 = namespace.addVariable({  
"organizedBy": isoInputs,  
"browseName": "I1",  
"nodeId": "ns=1;s=Isolated\_Input1",  
"dataType": "Double",  
"value": {  
"get": function() {  
return new Variant({  
"dataType": DataType.Double,  
"value": flexServerInternals.sandboxFlowContext.get("data1")  
});  
},  
"set": function(variant) {  
flexServerInternals.sandboxFlowContext.set(  
"isoInput1",  
parseFloat(variant.value)  
);  
return opcua.StatusCodes.Good;  
}  
}  
});

But when I try data type string as shown below, then it does not work, node status is always "waiting"  
const gpioDI1 = namespace.addVariable({  
"organizedBy": isoInputs,  
"browseName": "I1",  
"nodeId": "ns=1;s=String",  
"dataType": "String",  
"value": {  
"get": function() {  
return new Variant({  
"dataType": DataType.String,  
"value": flexServerInternals.sandboxFlowContext.get("data1")  
});  
},  
"set": function(variant) {  
flexServerInternals.sandboxFlowContext.set(  
"isoInput1",  
parseFloat(variant.value)  
);  
return opcua.StatusCodes.Good;  
}  
}  
});

the flow which is running perfectly is as below:

```auto
[
    {
        "id": "89c9e23040c05321",
        "type": "OPCUA-IIoT-Flex-Server",
        "z": "96df9d1b.b1b87",
        "port": "55480",
        "endpoint": "UA/user1",
        "acceptExternalCommands": true,
        "maxAllowedSessionNumber": "",
        "maxConnectionsPerEndpoint": "",
        "maxAllowedSubscriptionNumber": "",
        "alternateHostname": "",
        "name": "user1",
        "showStatusActivities": false,
        "showErrors": false,
        "allowAnonymous": true,
        "individualCerts": false,
        "isAuditing": false,
        "serverDiscovery": true,
        "users": [],
        "xmlsets": [],
        "publicCertificateFile": "",
        "privateCertificateFile": "",
        "registerServerMethod": "1",
        "discoveryServerEndpointUrl": "",
        "capabilitiesForMDNS": "",
        "maxNodesPerRead": 1000,
        "maxNodesPerBrowse": 2000,
        "delayToClose": 1000,
        "addressSpaceScript": "function constructAlarmAddressSpace(server, addressSpace, eventObjects, done) {\n // server = the created node-opcua server\n // addressSpace = script placeholder\n // eventObjects = to hold event variables in memory from this script\n \n // internal global sandbox objects are \n // node = node of the flex server, \n // coreServer = core iiot server object for debug and access to nodeOPCUA,\n // and scriptObjects to hold variables and functions\n const LocalizedText = opcua.LocalizedText;\n const namespace = addressSpace.getOwnNamespace();\n \n coreServer.internalDebugLog('init dynamic address space')\n node.warn('construct new address space for OPC UA')\n \n const Variant = opcua.Variant;\n const DataType = opcua.DataType;\n const DataValue = opcua.DataValue;\n \n var flexServerInternals = this;\n \n this.sandboxFlowContext.set(\"data1\", 0);\n this.sandboxFlowContext.set(\"data2\", 0);\n \n \n this.sandboxFlowContext.set(\"data3\", 0);\n this.sandboxFlowContext.set(\"data4\", 0);\n \n \n coreServer.internalDebugLog(\"init dynamic address space\");\n const rootFolder = addressSpace.findNode(\"RootFolder\");\n \n node.warn(\"construct new address space for OPC UA\");\n \n const myDevice = namespace.addFolder(rootFolder.objects, {\n \"browseName\": \"GNA_Scanner\"\n });\n const gpioFolder = namespace.addFolder(myDevice, { \"browseName\": \"GPIO\" });\n const isoInputs = namespace.addFolder(gpioFolder, {\n \"browseName\": \"Inputs\"\n });\n const isoOutputs = namespace.addFolder(gpioFolder, {\n \"browseName\": \"Outputs\"\n });\n \n const gpioDI1 = namespace.addVariable({\n \"organizedBy\": isoInputs,\n \"browseName\": \"I1\",\n \"nodeId\": \"ns=1;s=Isolated_Input1\",\n \"dataType\": \"Double\",\n \"value\": {\n \"get\": function() {\n return new Variant({\n \"dataType\": DataType.Double,\n \"value\": flexServerInternals.sandboxFlowContext.get(\"data1\")\n });\n },\n \"set\": function(variant) {\n flexServerInternals.sandboxFlowContext.set(\n \"isoInput1\",\n variant.value\n );\n return opcua.StatusCodes.Good;\n }\n }\n });\n \n const gpioDI2 = namespace.addVariable({\n \"organizedBy\": isoInputs,\n \"browseName\": \"I2\",\n \"nodeId\": \"ns=1;s=Isolated_Input2\",\n \"dataType\": \"Double\",\n \"value\": {\n \"get\": function() {\n return new Variant({\n \"dataType\": DataType.Double,\n \"value\": flexServerInternals.sandboxFlowContext.get(\"data2\")\n });\n },\n \"set\": function(variant) {\n flexServerInternals.sandboxFlowContext.set(\n \"isoInput2\",\n parseFloat(variant.value)\n );\n return opcua.StatusCodes.Good;\n }\n }\n });\n \n const gpioDO1 = namespace.addVariable({\n \"organizedBy\": isoOutputs,\n \"browseName\": \"O1\",\n \"nodeId\": \"ns=1;s=Isolated_Output1\",\n \"dataType\": \"Double\",\n \"value\": {\n \"get\": function() {\n return new Variant({\n \"dataType\": DataType.Double,\n \"value\": flexServerInternals.sandboxFlowContext.get(\"data3\")\n });\n },\n \"set\": function(variant) {\n flexServerInternals.sandboxFlowContext.set(\n \"isoOutput1\",\n parseFloat(variant.value)\n );\n return opcua.StatusCodes.Good;\n }\n }\n });\n \n const gpioDO2 = namespace.addVariable({\n \"organizedBy\": isoOutputs,\n \"browseName\": \"O2\",\n \"nodeId\": \"ns=1;s=Isolated_Output2\",\n \"dataType\": \"Double\",\n \"value\": {\n \"get\": function() {\n return new Variant({\n \"dataType\": DataType.Double,\n \"value\": flexServerInternals.sandboxFlowContext.get(\"data4\")\n });\n },\n \"set\": function(variant) {\n flexServerInternals.sandboxFlowContext.set(\n \"isoOutput2\",\n parseFloat(variant.value)\n );\n return opcua.StatusCodes.Good;\n }\n }\n });\n \n \n //------------------------------------------------------------------------------\n // Add a view\n //------------------------------------------------------------------------------\n const viewDI = namespace.addView({\n \"organizedBy\": rootFolder.views,\n \"browseName\": \"RPIW0-Digital-Ins\"\n });\n \n const viewDO = namespace.addView({\n \"organizedBy\": rootFolder.views,\n \"browseName\": \"RPIW0-Digital-Outs\"\n });\n \n viewDI.addReference({\n \"referenceType\": \"Organizes\",\n \"nodeId\": gpioDI1.nodeId\n });\n \n viewDI.addReference({\n \"referenceType\": \"Organizes\",\n \"nodeId\": gpioDI2.nodeId\n });\n \n \n viewDO.addReference({\n \"referenceType\": \"Organizes\",\n \"nodeId\": gpioDO1.nodeId\n });\n \n viewDO.addReference({\n \"referenceType\": \"Organizes\",\n \"nodeId\": gpioDO2.nodeId\n });\n \n \n coreServer.internalDebugLog(\"create dynamic address space done\");\n node.warn(\"construction of new address space for OPC UA done\");\n \n done();\n}\n",
        "x": 670,
        "y": 440,
        "wires": [
            []
        ]
    },
    {
        "id": "d322f02a5173c846",
        "type": "function",
        "z": "96df9d1b.b1b87",
        "name": "set flow context Inputs",
        "func": "flow.set('data1', 999)\nflow.set('data2', Math.random() + 13.0)\nflow.set('data3', Math.random() + 14.0)\nflow.set('data4', Math.random() + 15.0)\n\nmsg.payload = [\n flow.get('data1'),\n flow.get('data2'),\n flow.get('data3'),\n flow.get('data4'),\n]\nreturn msg;",
        "outputs": 1,
        "noerr": 0,
        "initialize": "",
        "finalize": "",
        "libs": [],
        "x": 460,
        "y": 380,
        "wires": [
            [
                "be3de210a03c018d"
            ]
        ]
    },
    {
        "id": "cc009cd686d0639d",
        "type": "inject",
        "z": "96df9d1b.b1b87",
        "name": "",
        "props": [
            {
                "p": "payload"
            },
            {
                "p": "topic",
                "vt": "str"
            }
        ],
        "repeat": "3",
        "crontab": "",
        "once": true,
        "onceDelay": "0.5",
        "topic": "",
        "payload": "",
        "payloadType": "date",
        "x": 250,
        "y": 380,
        "wires": [
            [
                "d322f02a5173c846"
            ]
        ]
    },
    {
        "id": "be3de210a03c018d",
        "type": "debug",
        "z": "96df9d1b.b1b87",
        "name": "debug 1",
        "active": false,
        "tosidebar": true,
        "console": false,
        "tostatus": false,
        "complete": "false",
        "statusVal": "",
        "statusType": "auto",
        "x": 680,
        "y": 380,
        "wires": []
    }
]

```

and the flow which is not working is as below:

```auto
[
    {
        "id": "89c9e23040c05321",
        "type": "OPCUA-IIoT-Flex-Server",
        "z": "96df9d1b.b1b87",
        "port": "55480",
        "endpoint": "UA/user1",
        "acceptExternalCommands": true,
        "maxAllowedSessionNumber": "",
        "maxConnectionsPerEndpoint": "",
        "maxAllowedSubscriptionNumber": "",
        "alternateHostname": "",
        "name": "user1",
        "showStatusActivities": false,
        "showErrors": false,
        "allowAnonymous": true,
        "individualCerts": false,
        "isAuditing": false,
        "serverDiscovery": true,
        "users": [],
        "xmlsets": [],
        "publicCertificateFile": "",
        "privateCertificateFile": "",
        "registerServerMethod": "1",
        "discoveryServerEndpointUrl": "",
        "capabilitiesForMDNS": "",
        "maxNodesPerRead": 1000,
        "maxNodesPerBrowse": 2000,
        "delayToClose": 1000,
        "addressSpaceScript": "function constructAlarmAddressSpace(server, addressSpace, eventObjects, done) {\n // server = the created node-opcua server\n // addressSpace = script placeholder\n // eventObjects = to hold event variables in memory from this script\n \n // internal global sandbox objects are \n // node = node of the flex server, \n // coreServer = core iiot server object for debug and access to nodeOPCUA,\n // and scriptObjects to hold variables and functions\n const LocalizedText = opcua.LocalizedText;\n const namespace = addressSpace.getOwnNamespace();\n \n coreServer.internalDebugLog('init dynamic address space')\n node.warn('construct new address space for OPC UA')\n \n const Variant = opcua.Variant;\n const DataType = opcua.DataType;\n const DataValue = opcua.DataValue;\n \n var flexServerInternals = this;\n \n this.sandboxFlowContext.set(\"data1\", 0);\n this.sandboxFlowContext.set(\"data2\", 0);\n \n \n this.sandboxFlowContext.set(\"data3\", 0);\n this.sandboxFlowContext.set(\"data4\", 0);\n \n \n coreServer.internalDebugLog(\"init dynamic address space\");\n const rootFolder = addressSpace.findNode(\"RootFolder\");\n \n node.warn(\"construct new address space for OPC UA\");\n \n const myDevice = namespace.addFolder(rootFolder.objects, {\n \"browseName\": \"GNA_Scanner\"\n });\n const gpioFolder = namespace.addFolder(myDevice, { \"browseName\": \"GPIO\" });\n const isoInputs = namespace.addFolder(gpioFolder, {\n \"browseName\": \"Inputs\"\n });\n const isoOutputs = namespace.addFolder(gpioFolder, {\n \"browseName\": \"Outputs\"\n });\n \n const gpioDI1 = namespace.addVariable({\n \"organizedBy\": isoInputs,\n \"browseName\": \"I1\",\n \"nodeId\": \"ns=1;s=Isolated_Input1\",\n \"dataType\": \"String\",\n \"value\": {\n \"get\": function() {\n return new Variant({\n \"dataType\": DataType.String,\n \"value\": flexServerInternals.sandboxFlowContext.get(\"data1\")\n });\n },\n \"set\": function(variant) {\n flexServerInternals.sandboxFlowContext.set(\n \"isoInput1\",\n variant.value\n );\n return opcua.StatusCodes.Good;\n }\n }\n });\n \n const gpioDI2 = namespace.addVariable({\n \"organizedBy\": isoInputs,\n \"browseName\": \"I2\",\n \"nodeId\": \"ns=1;s=Isolated_Input2\",\n \"dataType\": \"Double\",\n \"value\": {\n \"get\": function() {\n return new Variant({\n \"dataType\": DataType.Double,\n \"value\": flexServerInternals.sandboxFlowContext.get(\"data2\")\n });\n },\n \"set\": function(variant) {\n flexServerInternals.sandboxFlowContext.set(\n \"isoInput2\",\n parseFloat(variant.value)\n );\n return opcua.StatusCodes.Good;\n }\n }\n });\n \n const gpioDO1 = namespace.addVariable({\n \"organizedBy\": isoOutputs,\n \"browseName\": \"O1\",\n \"nodeId\": \"ns=1;s=Isolated_Output1\",\n \"dataType\": \"Double\",\n \"value\": {\n \"get\": function() {\n return new Variant({\n \"dataType\": DataType.Double,\n \"value\": flexServerInternals.sandboxFlowContext.get(\"data3\")\n });\n },\n \"set\": function(variant) {\n flexServerInternals.sandboxFlowContext.set(\n \"isoOutput1\",\n parseFloat(variant.value)\n );\n return opcua.StatusCodes.Good;\n }\n }\n });\n \n const gpioDO2 = namespace.addVariable({\n \"organizedBy\": isoOutputs,\n \"browseName\": \"O2\",\n \"nodeId\": \"ns=1;s=Isolated_Output2\",\n \"dataType\": \"Double\",\n \"value\": {\n \"get\": function() {\n return new Variant({\n \"dataType\": DataType.Double,\n \"value\": flexServerInternals.sandboxFlowContext.get(\"data4\")\n });\n },\n \"set\": function(variant) {\n flexServerInternals.sandboxFlowContext.set(\n \"isoOutput2\",\n parseFloat(variant.value)\n );\n return opcua.StatusCodes.Good;\n }\n }\n });\n \n \n //------------------------------------------------------------------------------\n // Add a view\n //------------------------------------------------------------------------------\n const viewDI = namespace.addView({\n \"organizedBy\": rootFolder.views,\n \"browseName\": \"RPIW0-Digital-Ins\"\n });\n \n const viewDO = namespace.addView({\n \"organizedBy\": rootFolder.views,\n \"browseName\": \"RPIW0-Digital-Outs\"\n });\n \n viewDI.addReference({\n \"referenceType\": \"Organizes\",\n \"nodeId\": gpioDI1.nodeId\n });\n \n viewDI.addReference({\n \"referenceType\": \"Organizes\",\n \"nodeId\": gpioDI2.nodeId\n });\n \n \n viewDO.addReference({\n \"referenceType\": \"Organizes\",\n \"nodeId\": gpioDO1.nodeId\n });\n \n viewDO.addReference({\n \"referenceType\": \"Organizes\",\n \"nodeId\": gpioDO2.nodeId\n });\n \n \n coreServer.internalDebugLog(\"create dynamic address space done\");\n node.warn(\"construction of new address space for OPC UA done\");\n \n done();\n}\n",
        "x": 670,
        "y": 440,
        "wires": [
            []
        ]
    },
    {
        "id": "d322f02a5173c846",
        "type": "function",
        "z": "96df9d1b.b1b87",
        "name": "set flow context Inputs",
        "func": "flow.set('data1', \"ABC1234\")\nflow.set('data2', Math.random() + 13.0)\nflow.set('data3', Math.random() + 14.0)\nflow.set('data4', Math.random() + 15.0)\n\nmsg.payload = [\n flow.get('data1'),\n flow.get('data2'),\n flow.get('data3'),\n flow.get('data4'),\n]\nreturn msg;",
        "outputs": 1,
        "noerr": 0,
        "initialize": "",
        "finalize": "",
        "libs": [],
        "x": 460,
        "y": 380,
        "wires": [
            [
                "be3de210a03c018d"
            ]
        ]
    },
    {
        "id": "cc009cd686d0639d",
        "type": "inject",
        "z": "96df9d1b.b1b87",
        "name": "",
        "props": [
            {
                "p": "payload"
            },
            {
                "p": "topic",
                "vt": "str"
            }
        ],
        "repeat": "3",
        "crontab": "",
        "once": true,
        "onceDelay": "0.5",
        "topic": "",
        "payload": "",
        "payloadType": "date",
        "x": 250,
        "y": 380,
        "wires": [
            [
                "d322f02a5173c846"
            ]
        ]
    },
    {
        "id": "be3de210a03c018d",
        "type": "debug",
        "z": "96df9d1b.b1b87",
        "name": "debug 1",
        "active": false,
        "tosidebar": true,
        "console": false,
        "tostatus": false,
        "complete": "false",
        "statusVal": "",
        "statusType": "auto",
        "x": 680,
        "y": 380,
        "wires": []
    }
]

```

Please suggest the solution to make second flow with string input working. thanks.

---

<div class="post-metadata">

**Author:** ![saraltech](https://avatars.discourse-cdn.com/v4/letter/s/71e660/32.png) [@saraltech](https://discourse.nodered.org/u/saraltech)\
**Post date:** [2 February 2023 02:14 UTC](https://discourse.nodered.org/t/how-to-define-data-type-string-for-opcua-iiot-flex-server-node/74503/2 "2023-02-02T02:14:07Z")

</div>

@Steve-Mcl , @mikakaraila : Can you please guide and support on this? Thanks a lot in advance.

---

<div class="post-metadata">

**Author:** ![mikakaraila](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/mikakaraila/32/37496_2.png) [@mikakaraila](https://discourse.nodered.org/u/mikakaraila)\
**Post date:** [2 February 2023 08:48 UTC](https://discourse.nodered.org/t/how-to-define-data-type-string-for-opcua-iiot-flex-server-node/74503/3 "2023-02-02T08:48:06Z")

</div>

> [@saraltech](#):
>
> parseFloat(variant.value)

Fix that link to be just variant.value

---

<div class="post-metadata">

**Author:** ![saraltech](https://avatars.discourse-cdn.com/v4/letter/s/71e660/32.png) [@saraltech](https://discourse.nodered.org/u/saraltech)\
**Post date:** [2 February 2023 11:37 UTC](https://discourse.nodered.org/t/how-to-define-data-type-string-for-opcua-iiot-flex-server-node/74503/4 "2023-02-02T11:37:19Z")

</div>

I had already tried it. It does not work.

---

<div class="post-metadata">

**Author:** ![saraltech](https://avatars.discourse-cdn.com/v4/letter/s/71e660/32.png) [@saraltech](https://discourse.nodered.org/u/saraltech)\
**Post date:** [2 February 2023 17:10 UTC](https://discourse.nodered.org/t/how-to-define-data-type-string-for-opcua-iiot-flex-server-node/74503/5 "2023-02-02T17:10:29Z")

</div>

Finally, I could find a way out by using:  
"dataType": "LocalizedText", (instead of String)

My new flow is pasted below , may be someone else can get some help.

```auto
[
    {
        "id": "38ce10de.7d8c",
        "type": "opcua-compact-server",
        "z": "2e8c7f5c.ab73d",
        "port": 54845,
        "endpoint": "",
        "productUri": "",
        "acceptExternalCommands": true,
        "maxAllowedSessionNumber": "10",
        "maxConnectionsPerEndpoint": "10",
        "maxAllowedSubscriptionNumber": "100",
        "alternateHostname": "",
        "name": "",
        "showStatusActivities": false,
        "showErrors": true,
        "allowAnonymous": true,
        "individualCerts": false,
        "isAuditing": false,
        "serverDiscovery": true,
        "users": [],
        "xmlsetsOPCUA": [],
        "publicCertificateFile": "",
        "privateCertificateFile": "",
        "registerServerMethod": "1",
        "discoveryServerEndpointUrl": "",
        "capabilitiesForMDNS": "",
        "maxNodesPerRead": 1000,
        "maxNodesPerWrite": 1000,
        "maxNodesPerHistoryReadData": 100,
        "maxNodesPerBrowse": 3000,
        "maxBrowseContinuationPoints": "10",
        "maxHistoryContinuationPoints": "10",
        "delayToInit": "1000",
        "delayToClose": "200",
        "serverShutdownTimeout": "100",
        "addressSpaceScript": "function constructAlarmAddressSpace(server, addressSpace, eventObjects, done) {\n // server = the created node-opcua server\n // addressSpace = address space of the node-opcua server\n // eventObjects = add event variables here to hold them in memory from this script\n\n // internal sandbox objects are:\n // node = the compact server node,\n // coreServer = core compact server object for debug and access to NodeOPCUA\n // this.sandboxNodeContext = node context node-red\n // this.sandboxFlowContext = flow context node-red\n // this.sandboxGlobalContext = global context node-red\n // this.sandboxEnv = env variables\n // timeout and interval functions as expected from nodejs\n\n const opcua = coreServer.choreCompact.opcua;\n const LocalizedText = opcua.LocalizedText;\n const namespace = addressSpace.getOwnNamespace();\n\n const Variant = opcua.Variant;\n const DataType = opcua.DataType;\n const DataValue = opcua.DataValue;\n\n var flexServerInternals = this;\n\n this.sandboxFlowContext.set(\"isoInput1\", 0);\n this.setInterval(() => {\n flexServerInternals.sandboxFlowContext.set(\n \"isoInput1\",\n Math.random() + 50.0\n );\n }, 500);\n this.sandboxFlowContext.set(\"isoInput2\", 0);\n this.sandboxFlowContext.set(\"isoInput3\", 0);\n this.sandboxFlowContext.set(\"isoInput4\", 0);\n this.sandboxFlowContext.set(\"isoInput5\", 0);\n this.sandboxFlowContext.set(\"isoInput6\", 0);\n this.sandboxFlowContext.set(\"isoInput7\", 0);\n this.sandboxFlowContext.set(\"isoInput8\", 0);\n\n this.sandboxFlowContext.set(\"isoOutput1\", 0);\n this.setInterval(() => {\n flexServerInternals.sandboxFlowContext.set(\n \"isoOutput1\",\n Math.random() + 10.0\n );\n }, 500);\n\n this.sandboxFlowContext.set(\"isoOutput2\", 0);\n this.sandboxFlowContext.set(\"isoOutput3\", 0);\n this.sandboxFlowContext.set(\"isoOutput4\", 0);\n this.sandboxFlowContext.set(\"isoOutput5\", 0);\n this.sandboxFlowContext.set(\"isoOutput6\", 0);\n this.sandboxFlowContext.set(\"isoOutput7\", 0);\n this.sandboxFlowContext.set(\"isoOutput8\", 0);\n\n coreServer.debugLog(\"init dynamic address space\");\n const rootFolder = addressSpace.findNode(\"RootFolder\");\n\n node.warn(\"construct new address space for OPC UA\");\n\n const myDevice = namespace.addFolder(rootFolder.objects, {\n \"browseName\": \"RaspberryPI-Zero-WLAN\"\n });\n const gpioFolder = namespace.addFolder(myDevice, { \"browseName\": \"GPIO\" });\n const isoInputs = namespace.addFolder(gpioFolder, {\n \"browseName\": \"Inputs\"\n });\n const isoOutputs = namespace.addFolder(gpioFolder, {\n \"browseName\": \"Outputs\"\n });\n\n const gpioDI1 = namespace.addVariable({\n \"organizedBy\": isoInputs,\n \"browseName\": \"I1\",\n \"nodeId\": \"ns=1;s=Isolated_Input1\",\n \"dataType\": \"Double\",\n \"value\": {\n \"get\": function() {\n return new Variant({\n \"dataType\": DataType.Double,\n \"value\": flexServerInternals.sandboxFlowContext.get(\"isoInput1\")\n });\n },\n \"set\": function(variant) {\n flexServerInternals.sandboxFlowContext.set(\n \"isoInput1\",\n parseFloat(variant.value)\n );\n return opcua.StatusCodes.Good;\n }\n }\n });\n\n const gpioDI2 = namespace.addVariable({\n \"organizedBy\": isoInputs,\n \"browseName\": \"I2\",\n \"nodeId\": \"ns=1;s=Isolated_Input2\",\n \"dataType\": \"LocalizedText\",\n \"value\": {\n \"get\": function() {\n return new Variant({\n \"dataType\": DataType.LocalizedText,\n \"value\": flexServerInternals.sandboxFlowContext.get(\"isoInput2\")\n });\n },\n \"set\": function(variant) {\n flexServerInternals.sandboxFlowContext.set(\n \"isoInput2\",\n variant.value\n );\n return opcua.StatusCodes.Good;\n }\n }\n });\n\n const gpioDI3 = namespace.addVariable({\n \"organizedBy\": isoInputs,\n \"browseName\": \"I3\",\n \"nodeId\": \"ns=1;s=Isolated_Input3\",\n \"dataType\": \"Double\",\n \"value\": {\n \"get\": function() {\n return new Variant({\n \"dataType\": DataType.Double,\n \"value\": flexServerInternals.sandboxFlowContext.get(\"isoInput3\")\n });\n },\n \"set\": function(variant) {\n flexServerInternals.sandboxFlowContext.set(\n \"isoInput3\",\n parseFloat(variant.value)\n );\n return opcua.StatusCodes.Good;\n }\n }\n });\n\n const gpioDI4 = namespace.addVariable({\n \"organizedBy\": isoInputs,\n \"browseName\": \"I4\",\n \"nodeId\": \"ns=1;s=Isolated_Input4\",\n \"dataType\": \"Double\",\n \"value\": {\n \"get\": function() {\n return new Variant({\n \"dataType\": DataType.Double,\n \"value\": flexServerInternals.sandboxFlowContext.get(\"isoInput4\")\n });\n },\n \"set\": function(variant) {\n flexServerInternals.sandboxFlowContext.set(\n \"isoInput4\",\n parseFloat(variant.value)\n );\n return opcua.StatusCodes.Good;\n }\n }\n });\n\n const gpioDI5 = namespace.addVariable({\n \"organizedBy\": isoInputs,\n \"browseName\": \"I5\",\n \"nodeId\": \"ns=1;s=Isolated_Input5\",\n \"dataType\": \"Double\",\n \"value\": {\n \"get\": function() {\n return new Variant({\n \"dataType\": DataType.Double,\n \"value\": flexServerInternals.sandboxFlowContext.get(\"isoInput5\")\n });\n },\n \"set\": function(variant) {\n flexServerInternals.sandboxFlowContext.set(\n \"isoInput5\",\n parseFloat(variant.value)\n );\n return opcua.StatusCodes.Good;\n }\n }\n });\n\n const gpioDI6 = namespace.addVariable({\n \"organizedBy\": isoInputs,\n \"browseName\": \"I6\",\n \"nodeId\": \"ns=1;s=Isolated_Input6\",\n \"dataType\": \"Double\",\n \"value\": {\n \"get\": function() {\n return new Variant({\n \"dataType\": DataType.Double,\n \"value\": flexServerInternals.sandboxFlowContext.get(\"isoInput6\")\n });\n },\n \"set\": function(variant) {\n flexServerInternals.sandboxFlowContext.set(\n \"isoInput6\",\n parseFloat(variant.value)\n );\n return opcua.StatusCodes.Good;\n }\n }\n });\n\n const gpioDI7 = namespace.addVariable({\n \"organizedBy\": isoInputs,\n \"browseName\": \"I7\",\n \"nodeId\": \"ns=1;s=Isolated_Input7\",\n \"dataType\": \"Double\",\n \"value\": {\n \"get\": function() {\n return new Variant({\n \"dataType\": DataType.Double,\n \"value\": flexServerInternals.sandboxFlowContext.get(\"isoInput7\")\n });\n },\n \"set\": function(variant) {\n flexServerInternals.sandboxFlowContext.set(\n \"isoInput7\",\n parseFloat(variant.value)\n );\n return opcua.StatusCodes.Good;\n }\n }\n });\n\n const gpioDI8 = namespace.addVariable({\n \"organizedBy\": isoInputs,\n \"browseName\": \"I8\",\n \"nodeId\": \"ns=1;s=Isolated_Input8\",\n \"dataType\": \"Double\",\n \"value\": {\n \"get\": function() {\n return new Variant({\n \"dataType\": DataType.Double,\n \"value\": flexServerInternals.sandboxFlowContext.get(\"isoInput8\")\n });\n },\n \"set\": function(variant) {\n flexServerInternals.sandboxFlowContext.set(\n \"isoInput8\",\n parseFloat(variant.value)\n );\n return opcua.StatusCodes.Good;\n }\n }\n });\n\n const gpioDO1 = namespace.addVariable({\n \"organizedBy\": isoOutputs,\n \"browseName\": \"O1\",\n \"nodeId\": \"ns=1;s=Isolated_Output1\",\n \"dataType\": \"Double\",\n \"value\": {\n \"get\": function() {\n return new Variant({\n \"dataType\": DataType.Double,\n \"value\": flexServerInternals.sandboxFlowContext.get(\"isoOutput1\")\n });\n },\n \"set\": function(variant) {\n flexServerInternals.sandboxFlowContext.set(\n \"isoOutput1\",\n parseFloat(variant.value)\n );\n return opcua.StatusCodes.Good;\n }\n }\n });\n\n const gpioDO2 = namespace.addVariable({\n \"organizedBy\": isoOutputs,\n \"browseName\": \"O2\",\n \"nodeId\": \"ns=1;s=Isolated_Output2\",\n \"dataType\": \"Double\",\n \"value\": {\n \"get\": function() {\n return new Variant({\n \"dataType\": DataType.Double,\n \"value\": flexServerInternals.sandboxFlowContext.get(\"isoOutput2\")\n });\n },\n \"set\": function(variant) {\n flexServerInternals.sandboxFlowContext.set(\n \"isoOutput2\",\n parseFloat(variant.value)\n );\n return opcua.StatusCodes.Good;\n }\n }\n });\n\n const gpioDO3 = namespace.addVariable({\n \"organizedBy\": isoOutputs,\n \"browseName\": \"O3\",\n \"nodeId\": \"ns=1;s=Isolated_Output3\",\n \"dataType\": \"Double\",\n \"value\": {\n \"get\": function() {\n return new Variant({\n \"dataType\": DataType.Double,\n \"value\": flexServerInternals.sandboxFlowContext.get(\"isoOutput3\")\n });\n },\n \"set\": function(variant) {\n flexServerInternals.sandboxFlowContext.set(\n \"isoOutput3\",\n parseFloat(variant.value)\n );\n return opcua.StatusCodes.Good;\n }\n }\n });\n\n const gpioDO4 = namespace.addVariable({\n \"organizedBy\": isoOutputs,\n \"browseName\": \"O4\",\n \"nodeId\": \"ns=1;s=Isolated_Output4\",\n \"dataType\": \"Double\",\n \"value\": {\n \"get\": function() {\n return new Variant({\n \"dataType\": DataType.Double,\n \"value\": flexServerInternals.sandboxFlowContext.get(\"isoOutput4\")\n });\n },\n \"set\": function(variant) {\n flexServerInternals.sandboxFlowContext.set(\n \"isoOutput4\",\n parseFloat(variant.value)\n );\n return opcua.StatusCodes.Good;\n }\n }\n });\n\n const gpioDO5 = namespace.addVariable({\n \"organizedBy\": isoOutputs,\n \"browseName\": \"O5\",\n \"nodeId\": \"ns=1;s=Isolated_Output5\",\n \"dataType\": \"Double\",\n \"value\": {\n \"get\": function() {\n return new Variant({\n \"dataType\": DataType.Double,\n \"value\": flexServerInternals.sandboxFlowContext.get(\"isoOutput5\")\n });\n },\n \"set\": function(variant) {\n flexServerInternals.sandboxFlowContext.set(\n \"isoOutput5\",\n parseFloat(variant.value)\n );\n return opcua.StatusCodes.Good;\n }\n }\n });\n\n const gpioDO6 = namespace.addVariable({\n \"organizedBy\": isoOutputs,\n \"browseName\": \"O6\",\n \"nodeId\": \"ns=1;s=Isolated_Output6\",\n \"dataType\": \"Double\",\n \"value\": {\n \"get\": function() {\n return new Variant({\n \"dataType\": DataType.Double,\n \"value\": flexServerInternals.sandboxFlowContext.get(\"isoOutput6\")\n });\n },\n \"set\": function(variant) {\n flexServerInternals.sandboxFlowContext.set(\n \"isoOutput6\",\n parseFloat(variant.value)\n );\n return opcua.StatusCodes.Good;\n }\n }\n });\n\n const gpioDO7 = namespace.addVariable({\n \"organizedBy\": isoOutputs,\n \"browseName\": \"O7\",\n \"nodeId\": \"ns=1;s=Isolated_Output7\",\n \"dataType\": \"Double\",\n \"value\": {\n \"get\": function() {\n return new Variant({\n \"dataType\": DataType.Double,\n \"value\": flexServerInternals.sandboxFlowContext.get(\"isoOutput7\")\n });\n },\n \"set\": function(variant) {\n flexServerInternals.sandboxFlowContext.set(\n \"isoOutput7\",\n parseFloat(variant.value)\n );\n return opcua.StatusCodes.Good;\n }\n }\n });\n\n const gpioDO8 = namespace.addVariable({\n \"organizedBy\": isoOutputs,\n \"browseName\": \"O8\",\n \"nodeId\": \"ns=1;s=Isolated_Output8\",\n \"dataType\": \"Double\",\n \"value\": {\n \"get\": function() {\n return new Variant({\n \"dataType\": DataType.Double,\n \"value\": flexServerInternals.sandboxFlowContext.get(\"isoOutput8\")\n });\n },\n \"set\": function(variant) {\n flexServerInternals.sandboxFlowContext.set(\n \"isoOutput8\",\n parseFloat(variant.value)\n );\n return opcua.StatusCodes.Good;\n }\n }\n });\n\n //------------------------------------------------------------------------------\n // Add a view\n //------------------------------------------------------------------------------\n const viewDI = namespace.addView({\n \"organizedBy\": rootFolder.views,\n \"browseName\": \"RPIW0-Digital-Ins\"\n });\n\n const viewDO = namespace.addView({\n \"organizedBy\": rootFolder.views,\n \"browseName\": \"RPIW0-Digital-Outs\"\n });\n\n viewDI.addReference({\n \"referenceType\": \"Organizes\",\n \"nodeId\": gpioDI1.nodeId\n });\n\n viewDI.addReference({\n \"referenceType\": \"Organizes\",\n \"nodeId\": gpioDI2.nodeId\n });\n\n viewDI.addReference({\n \"referenceType\": \"Organizes\",\n \"nodeId\": gpioDI3.nodeId\n });\n\n viewDI.addReference({\n \"referenceType\": \"Organizes\",\n \"nodeId\": gpioDI4.nodeId\n });\n\n viewDI.addReference({\n \"referenceType\": \"Organizes\",\n \"nodeId\": gpioDI5.nodeId\n });\n\n viewDI.addReference({\n \"referenceType\": \"Organizes\",\n \"nodeId\": gpioDI6.nodeId\n });\n\n viewDI.addReference({\n \"referenceType\": \"Organizes\",\n \"nodeId\": gpioDI7.nodeId\n });\n\n viewDI.addReference({\n \"referenceType\": \"Organizes\",\n \"nodeId\": gpioDI8.nodeId\n });\n\n viewDO.addReference({\n \"referenceType\": \"Organizes\",\n \"nodeId\": gpioDO1.nodeId\n });\n\n viewDO.addReference({\n \"referenceType\": \"Organizes\",\n \"nodeId\": gpioDO2.nodeId\n });\n\n viewDO.addReference({\n \"referenceType\": \"Organizes\",\n \"nodeId\": gpioDO3.nodeId\n });\n\n viewDO.addReference({\n \"referenceType\": \"Organizes\",\n \"nodeId\": gpioDO4.nodeId\n });\n\n viewDO.addReference({\n \"referenceType\": \"Organizes\",\n \"nodeId\": gpioDO5.nodeId\n });\n\n viewDO.addReference({\n \"referenceType\": \"Organizes\",\n \"nodeId\": gpioDO6.nodeId\n });\n\n viewDO.addReference({\n \"referenceType\": \"Organizes\",\n \"nodeId\": gpioDO7.nodeId\n });\n\n viewDO.addReference({\n \"referenceType\": \"Organizes\",\n \"nodeId\": gpioDO8.nodeId\n });\n\n coreServer.debugLog(\"create dynamic address space done\");\n node.warn(\"construction of new address space for OPC UA done\");\n\n done();\n}\n",
        "x": 380,
        "y": 480,
        "wires": []
    },
    {
        "id": "eea020c4.58aa",
        "type": "inject",
        "z": "2e8c7f5c.ab73d",
        "name": "",
        "repeat": "1",
        "crontab": "",
        "once": true,
        "onceDelay": "0.5",
        "topic": "",
        "payload": "",
        "payloadType": "date",
        "x": 230,
        "y": 120,
        "wires": [
            [
                "11876179.c98d97"
            ]
        ]
    },
    {
        "id": "11876179.c98d97",
        "type": "function",
        "z": "2e8c7f5c.ab73d",
        "name": "set flow context Inputs",
        "func": "// flow.set('isoInput1', Math.random() + 11.0) interval comes from server\n//flow.set('isoInput2', \"777GNA777\")\nflow.set('isoInput3', Math.random() + 13.0)\nflow.set('isoInput4', Math.random() + 14.0)\nflow.set('isoInput5', Math.random() + 15.0)\nflow.set('isoInput6', Math.random() + 16.0)\nflow.set('isoInput7', Math.random() + 17.0)\nflow.set('isoInput8', Math.random() + 18.0)\n\nmsg.payload = [\n flow.get('isoInput1'),\n flow.get('isoInput2'),\n flow.get('isoInput3'),\n flow.get('isoInput4'),\n flow.get('isoInput5'),\n flow.get('isoInput6'),\n flow.get('isoInput7'),\n flow.get('isoInput8'),\n]\nreturn msg;",
        "outputs": 1,
        "noerr": 0,
        "initialize": "",
        "finalize": "",
        "libs": [],
        "x": 470,
        "y": 120,
        "wires": [
            [
                "c49994c7.8f5cc"
            ]
        ]
    },
    {
        "id": "c49994c7.8f5cc",
        "type": "debug",
        "z": "2e8c7f5c.ab73d",
        "name": "",
        "active": false,
        "tosidebar": true,
        "console": false,
        "tostatus": false,
        "complete": "false",
        "x": 720,
        "y": 120,
        "wires": []
    },
    {
        "id": "71946cf3.646e14",
        "type": "function",
        "z": "2e8c7f5c.ab73d",
        "name": "set flow context Outputs",
        "func": "// flow.set('isoOutput1', Math.random() + 1.0) interval comes from server\nflow.set('isoOutput2', Math.random() + 2.0)\nflow.set('isoOutput3', Math.random() + 3.0)\nflow.set('isoOutput4', Math.random() + 4.0)\nflow.set('isoOutput5', Math.random() + 5.0)\nflow.set('isoOutput6', Math.random() + 6.0)\nflow.set('isoOutput7', Math.random() + 7.0)\nflow.set('isoOutput8', Math.random() + 8.0)\n\nmsg.payload = [\n flow.get('isoOutput1'),\n flow.get('isoOutput2'),\n flow.get('isoOutput3'),\n flow.get('isoOutput4'),\n flow.get('isoOutput5'),\n flow.get('isoOutput6'),\n flow.get('isoOutput7'),\n flow.get('isoOutput8'),\n]\nreturn msg;",
        "outputs": 1,
        "noerr": 0,
        "x": 480,
        "y": 180,
        "wires": [
            [
                "4eebf9d5.8843d8"
            ]
        ]
    },
    {
        "id": "494d041a.83d17c",
        "type": "inject",
        "z": "2e8c7f5c.ab73d",
        "name": "",
        "repeat": "1",
        "crontab": "",
        "once": true,
        "onceDelay": "0.5",
        "topic": "",
        "payload": "",
        "payloadType": "date",
        "x": 230,
        "y": 180,
        "wires": [
            [
                "71946cf3.646e14"
            ]
        ]
    },
    {
        "id": "4eebf9d5.8843d8",
        "type": "debug",
        "z": "2e8c7f5c.ab73d",
        "name": "",
        "active": false,
        "tosidebar": true,
        "console": false,
        "tostatus": false,
        "complete": "false",
        "x": 720,
        "y": 180,
        "wires": []
    },
    {
        "id": "201afb2df36b6105",
        "type": "inject",
        "z": "2e8c7f5c.ab73d",
        "name": "",
        "props": [
            {
                "p": "payload"
            },
            {
                "p": "topic",
                "vt": "str"
            }
        ],
        "repeat": "",
        "crontab": "",
        "once": false,
        "onceDelay": 0.1,
        "topic": "",
        "payload": "",
        "payloadType": "date",
        "x": 280,
        "y": 280,
        "wires": [
            [
                "6c457c17aa17fd5e",
                "0d432b2272fa7e4c"
            ]
        ]
    },
    {
        "id": "6c457c17aa17fd5e",
        "type": "function",
        "z": "2e8c7f5c.ab73d",
        "name": "function 4",
        "func": "flow.set(\"isoInput2\", \"Hello NR Forum\")\nreturn msg;",
        "outputs": 1,
        "noerr": 0,
        "initialize": "",
        "finalize": "",
        "libs": [],
        "x": 640,
        "y": 280,
        "wires": [
            []
        ]
    },
    {
        "id": "bcc5b2b921d0fc27",
        "type": "function",
        "z": "2e8c7f5c.ab73d",
        "name": "function 5",
        "func": "flow.set(\"isoInput2\", \"Hello World!!\")\nreturn msg;",
        "outputs": 1,
        "noerr": 0,
        "initialize": "",
        "finalize": "",
        "libs": [],
        "x": 640,
        "y": 340,
        "wires": [
            []
        ]
    },
    {
        "id": "0d432b2272fa7e4c",
        "type": "delay",
        "z": "2e8c7f5c.ab73d",
        "name": "",
        "pauseType": "delay",
        "timeout": "5",
        "timeoutUnits": "seconds",
        "rate": "1",
        "nbRateUnits": "1",
        "rateUnits": "second",
        "randomFirst": "1",
        "randomLast": "5",
        "randomUnits": "seconds",
        "drop": false,
        "allowrate": false,
        "outputs": 1,
        "x": 480,
        "y": 380,
        "wires": [
            [
                "bcc5b2b921d0fc27",
                "9e4e37bd6969d111"
            ]
        ]
    },
    {
        "id": "9e4e37bd6969d111",
        "type": "delay",
        "z": "2e8c7f5c.ab73d",
        "name": "",
        "pauseType": "delay",
        "timeout": "5",
        "timeoutUnits": "seconds",
        "rate": "1",
        "nbRateUnits": "1",
        "rateUnits": "second",
        "randomFirst": "1",
        "randomLast": "5",
        "randomUnits": "seconds",
        "drop": false,
        "allowrate": false,
        "outputs": 1,
        "x": 300,
        "y": 380,
        "wires": [
            [
                "6c457c17aa17fd5e"
            ]
        ]
    },
    {
        "id": "ec609dc628930ab7",
        "type": "OpcUa-Client",
        "z": "2e8c7f5c.ab73d",
        "endpoint": "bc51f3974cda2b3f",
        "action": "read",
        "deadbandtype": "a",
        "deadbandvalue": 1,
        "time": 10,
        "timeUnit": "s",
        "certificate": "n",
        "localfile": "",
        "localkeyfile": "",
        "securitymode": "None",
        "securitypolicy": "None",
        "folderName4PKI": "",
        "name": "",
        "x": 620,
        "y": 580,
        "wires": [
            [
                "5cca9ccea1e628a5"
            ]
        ]
    },
    {
        "id": "1319777f1c772415",
        "type": "inject",
        "z": "2e8c7f5c.ab73d",
        "name": "",
        "props": [
            {
                "p": "payload"
            },
            {
                "p": "topic",
                "vt": "str"
            }
        ],
        "repeat": "3",
        "crontab": "",
        "once": false,
        "onceDelay": 0.1,
        "topic": "",
        "payload": "",
        "payloadType": "date",
        "x": 230,
        "y": 580,
        "wires": [
            [
                "1caf55a2a40b1c94"
            ]
        ]
    },
    {
        "id": "5cca9ccea1e628a5",
        "type": "debug",
        "z": "2e8c7f5c.ab73d",
        "name": "debug 2",
        "active": false,
        "tosidebar": true,
        "console": false,
        "tostatus": false,
        "complete": "false",
        "statusVal": "",
        "statusType": "auto",
        "x": 820,
        "y": 580,
        "wires": []
    },
    {
        "id": "1caf55a2a40b1c94",
        "type": "OpcUa-Item",
        "z": "2e8c7f5c.ab73d",
        "item": "ns=1;s=Isolated_Input2",
        "datatype": "String",
        "value": "",
        "name": "",
        "x": 420,
        "y": 580,
        "wires": [
            [
                "ec609dc628930ab7"
            ]
        ]
    },
    {
        "id": "bc51f3974cda2b3f",
        "type": "OpcUa-Endpoint",
        "endpoint": "opc.tcp://localhost:54845/UA/NodeRED/Compact",
        "secpol": "None",
        "secmode": "None",
        "none": true,
        "login": false,
        "usercert": false,
        "usercertificate": "",
        "userprivatekey": ""
    }
]

```

Thanks NR Forum.

---

<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/1X/d073cd938eafa2e558d7c2cd59003b3ef4963033.png) [@system](https://discourse.nodered.org/u/system)\
**Post date:** [16 February 2023 17:11 UTC](https://discourse.nodered.org/t/how-to-define-data-type-string-for-opcua-iiot-flex-server-node/74503/6 "2023-02-16T17:11:29Z")

</div>

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