20 lines
827 B
JavaScript
20 lines
827 B
JavaScript
// 'RIR' contains the "Function Code" that we are going to invoke on the remote device
|
|
var FC = require('modbus-stack').FUNCTION_CODES;
|
|
|
|
// IP and port of the MODBUS slave, default port is 502
|
|
var client = require('modbus-stack/client').createClient(502, 'localhost');
|
|
|
|
// 'req' is an instance of the low-level `ModbusRequestStack` class
|
|
var req = client.request(FC.READ_INPUT_REGISTERS, // Function Code: 4
|
|
0, // Start at address 0
|
|
50) // Read 50 contiguous registers from 0
|
|
.on('error', function (err) {
|
|
console.error(err);
|
|
});
|
|
|
|
// 'response' is emitted after the entire contents of the response has been received.
|
|
req.on('response', function(registers) {
|
|
// An Array of length 50 filled with Numbers of the current registers.
|
|
console.log(registers);
|
|
client.end();
|
|
}); |