diff --git a/services/serialPortService.js b/services/serialPortService.js
index 427b66d..caff0cf 100644
--- a/services/serialPortService.js
+++ b/services/serialPortService.js
@@ -23,7 +23,7 @@ async function serialPortList(req, res) {
           console.log(111111, serialPort)
 
           const buff = Buffer.allocUnsafe(4);
-          buff.writeUInt8(`#0${req.params.id}$`);
+          buff.write(`#0${req.params.id}$`);
 
           serialPort.write(buff)
         }