im trying to build a html scada system using nodejs , php , html and css.
my program : i have this little 9 lines code in nodejs ; i use this code to communicat with a PLC in modbus rtu protocol. the code is working perfectly if i run it from terminal ;
my problem : im trying to run this code usinga php submit button inside html page, but i think that i missing something cuz its not working.
thank you . nodejs code :
// create an empty modbus client
var ModbusRTU = require("modbus-serial");
var client = new ModbusRTU();
// open connection to a serial port
client.connectRTUBuffered("COM2", { baudRate: 9600 ,parity: "even", dataBits: 8, stopBits: 1} , write );
function write() {
client.writeCoil(22, 1);
}
html code : :
<html>
<head>
<title>PHP isset() example</title>
</head>
<body>
<form method="post">
<input type="submit" value="Sum" name="Submit1"><br/><br/>
<?php
if(isset($_POST["Submit1"]))
{
exec('write.js >/dev/null/ 2>&1 &');
}
?>
</form>
<script src="write.js" type="text/javascript" ></script>
</body>
</html>
You want to execute a js file which is not possible without an interpreter. Your exec code should look like this:
exec('node write.js')
Here node is the executable of you node instance.