# ACCESS DENIED when using serialport in node-red
**URL:** https://discourse.nodered.org/t/access-denied-when-using-serialport-in-node-red/89496
**Category:** General
**Tags:** node-red-node-serialport
**Created:** [15 July 2024 02:04 UTC](https://discourse.nodered.org/t/access-denied-when-using-serialport-in-node-red/89496 "2024-07-15T02:04:58Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@xty19](https://discourse.nodered.org/u/xty19)
#### Post date: [15 July 2024 02:04 UTC](https://discourse.nodered.org/t/access-denied-when-using-serialport-in-node-red/89496/1 "2024-07-15T02:04:58Z")
SerialPort Version
12.0.0
Node Version
V18.16.1 (MACOS) V20.15.0(WIN10,WIN11 )
Electron Version
No response
Platform
MACOS12.1 WIN11 WIN10
Architecture
x64
Hardware or chipset of serialport
FT232R USB UART
I use serialport and I use it in node-red MACOS OS,and it runs good. But when It runs on WIN10 or WIN11 , it occurs some problems. ACCESS DENIED. It took me 3days ,and finally I found .When I close the port ,even add await function ,It still cant close clearly.I have to add some delay to solve the problem.
So can anyone find the solution？
The json code:
```javascript
[
{
"id": "babef08263e2071a",
"type": "function",
"z": "f9e5abd85425a547",
"name": "single",
"func": "var { SerialPort } = global.get('require')('serialport');\nvar delay = 150\nconst receiveDelay = delay; // 接收延迟时间，单位：毫秒\nconst writeDelay = delay; // 接收延迟时间，单位：毫秒\n// serialport profile 获取串口配置\nvar portConfig = {\n port: \"COM3\", // 串口名称，请根据实际情况修改\n baudRate: 2400,\n dataBits: 8,\n stopBits: 1,\n parity: \"None\",\n};\n\n// instance ,创建串口实例\nvar port \nnode.warn(\"@@@ msg:\")\n\ntry {\n port = new SerialPort({\n path: portConfig.port,\n baudRate: portConfig.baudRate,\n dataBits: portConfig.dataBits,\n stopBits: portConfig.stopBits,\n parity: portConfig.parity,\n });\n \n // node.warn('@@flow.get(port_flow1):' + flow.get('port_flow1'));\n // port=flow.get('port_flow1')||0;\n // port = new SerialPort({\n // path: portConfig.port,\n // baudRate: portConfig.baudRate,\n // dataBits: portConfig.dataBits,\n // stopBits: portConfig.stopBits,\n // parity: portConfig.parity,\n // }); \n // flow.set(\"port_flow1\",port)\n node.warn('@@port.isOpen?：' + port.isOpen);\n\n} catch (error) {\n node.warn('开启串口时发生错误：' + error);\n getStackTrace();\n onClose();\n};\n\n//send data async 发送数据的异步函数\nvar sendData = async function (data) {\n return new Promise(function (resolve, reject) {\n try {\n port.write(data, function (err) {\n if (err) {\n reject(err);\n } else {\n resolve();\n }\n });\n } catch (error) {\n getStackTrace();\n onClose()\n }finally{\n }\n });\n};\n\n//receive data sync 接收数据的异步函数\nvar receiveData = async function () {\n return new Promise(function (resolve) {\n var dataTimeout = setTimeout(function () {\n //a delay not wait 设置一个超时，防止永远等待\n resolve('');\n }, receiveDelay);\n try {\n port.on('data', function (data) {\n clearTimeout(dataTimeout);\n resolve(data.toString('hex'));\n });\n } catch (error) {\n getStackTrace();\n onClose()\n node.warn(\"@@@receiveData catch\")\n } finally {\n }\n });\n};\n// main 主处理逻辑\nasync function processInput(msg) {\n try {\n // send data发送数据\n var temp_command = '010300000001840A '\n var dataToSend = Buffer.from(temp_command, 'hex');\n await sendData(dataToSend);\n // 等待1秒\n await new Promise(function (resolve) {\n setTimeout(resolve, writeDelay);\n });\n // 接收数据\n var receivedData = await receiveData();\n // 返回结果\n if (receivedData!='')\n {\n node.warn(\"@received:\" + receivedData);\n }\n } catch (error) {\n // 发生错误时处理\n node.error(error.message, msg);\n }finally{\n onClose().then(()=>{ //then添加\n node.warn(\"@@@then\")\n node.warn('@@sending msg port.isOpen?：' + port.isOpen);\n node.send(msg);\n })\n }\n}\n// 在节点关闭时关闭串口\nasync function onClose() {\n node.warn('@@@ port is closing');\n if (port.isOpen) {\n port.close((err) => {\n if (err) {\n node.warn('关闭串口时发生错误：' + err.message);\n } else {\n node.warn('串口成功关闭');\n node.warn('关闭port.isOpen：' + port.isOpen);\n }\n });\n }\n else{\n node.warn('串口早已关闭');\n }\n}\n\nvar getStackTrace = function() {\n var obj = {};\n Error.captureStackTrace(obj, getStackTrace);\n node.warn(\"Location:\" + (obj.stack).split(/\\n+/)[1].replace(/(^\\s+|\\s+$)/,\"\"));\n};\n\ntry {\n getStackTrace();\n processInput(msg);\n} catch (error) {\n node.warn('processInput 发生错误:' + error.message);\n}finally{\n getStackTrace();\n onClose()\n}\n\n// 在 Function 节点中监听关闭事件，用于关闭串口\nnode.on('close', function () {\n // node.warn('close');\n getStackTrace();\n onClose();\n});\n",
"outputs": 1,
"timeout": "",
"noerr": 0,
"initialize": "",
"finalize": "",
"libs": [],
"x": 455.4513854980469,
"y": 280.44964599609375,
"wires": [
[]
]
},
{
"id": "7bd41a4973ab38d1",
"type": "inject",
"z": "f9e5abd85425a547",
"name": "",
"props": [
{
"p": "topic",
"vt": "str"
}
],
"repeat": "",
"crontab": "",
"once": false,
"onceDelay": 0.1,
"topic": "",
"x": 315.4513854980469,
"y": 280.44964599609375,
"wires": [
[
"babef08263e2071a"
]
]
}
]
```
You can touch the inject button to test,when you touch too fast ,it occurs "[red] Uncaught Exception:
[error] Error: Opening COM3: Access denied"
---
### Author:  [@dceejay](https://discourse.nodered.org/u/dceejay)
#### Post date: [15 July 2024 07:25 UTC](https://discourse.nodered.org/t/access-denied-when-using-serialport-in-node-red/89496/2 "2024-07-15T07:25:12Z")
Maybe need to call done() when you have finished closing the port so the rest of the runtime knows. eg see the serial port node code - [node-red-nodes/io/serialport/25-serial.js at cd6bbb3e69e74d17db4e4e98ad6a6b68ba6b008b · node-red/node-red-nodes · GitHub](https://github.com/node-red/node-red-nodes/blob/cd6bbb3e69e74d17db4e4e98ad6a6b68ba6b008b/io/serialport/25-serial.js#L223)
---
### Author:  [@xty19](https://discourse.nodered.org/u/xty19)
#### Post date: [15 July 2024 13:37 UTC](https://discourse.nodered.org/t/access-denied-when-using-serialport-in-node-red/89496/3 "2024-07-15T13:37:10Z")
Many thanks，I try it now
---
### Author:  [@system](https://discourse.nodered.org/u/system)
#### Post date: [13 October 2024 13:37 UTC](https://discourse.nodered.org/t/access-denied-when-using-serialport-in-node-red/89496/4 "2024-10-13T13:37:27Z")
This topic was automatically closed 90 days after the last reply. New replies are no longer allowed.