Implementation for the Serial/TCP Modbus protocol.
A simple an easy to use Modbus TCP client/server implementation.
Modbus 
========
Modbus is a simple Modbus TCP Client with a simple API.
Releases
------------
Version 2.0 has serialport 6.2.2 for testing purposes.
Version 3.0 has serialport 8.0.8 for testing purposes.
Version 3.1 has serialport 9.0.7.
Installation
------------
Just type npm install @mksea/jsmodbus and you are ready to go.
Testing
-------
The test files are implemented using mocha and sinon.
Simply npm install -g mocha and npm install -g sinon. To run the tests type from the projects root folder mocha test/*.
Please feel free to fork and add your own tests.
TCP Client example
--------------
``javascript
`
var modbus = require('jsmodbus');
// create a modbus client
var client = modbus.client.tcp.complete({
'host' : host,
'port' : port,
'autoReconnect' : true,
'reconnectTimeout' : 1000,
'timeout' : 5000,
'unitId' : 0
});
client.connect();
// reconnect with client.reconnect()
client.on('connect', function () {
// make some calls
client.readCoils(0, 13).then(function (resp) {
// resp will look like { fc: 1, byteCount: 20, coils: [ values 0 - 13 ], payload:
console.log(resp);
}, console.error);
client.readDiscreteInputs(0, 13).then(function (resp) {
// resp will look like { fc: 2, byteCount: 20, coils: [ values 0 - 13 ], payload:
console.log(resp);
}, console.error);
client.readHoldingRegisters(0, 10).then(function (resp) {
// resp will look like { fc: 3, byteCount: 20, register: [ values 0 - 10 ], payload:
console.log(resp);
}, console.error);
client.readInputRegisters(0, 10).then(function (resp) {
// resp will look like { fc: 4, byteCount: 20, register: [ values 0 - 10 ], payload:
console.log(resp);
}, console.error);
client.writeSingleCoil(5, true).then(function (resp) {
// resp will look like { fc: 5, byteCount: 4, outputAddress: 5, outputValue: true }
console.log(resp);
}, console.error);
client.writeSingleCoil(5, Buffer.from([0x01])).then(function (resp) {
// resp will look like { fc: 5, byteCount: 4, outputAddress: 5, outputValue: true }
console.log(resp);
}, console.error);
client.writeSingleRegister(13, 42).then(function (resp) {
// resp will look like { fc: 6, byteCount: 4, registerAddress: 13, registerValue: 42 }
console.log(resp);
}, console.error);
client.writeSingleRegister(13, Buffer.from([0x00, 0x2A])).then(function (resp) {
// resp will look like { fc: 6, byteCount: 4, registerAddress: 13, registerValue: 42 }
console.log(resp);
}, console.error);
client.writeMultipleCoils(3, [1, 0, 1, 0, 1, 1]).then(function (resp) {
// resp will look like { fc: 15, startAddress: 3, quantity: 6 }
console.log(resp);
}, console.error);
client.writeMultipleCoils(3, Buffer.from([0x2B]), 6).then(function (resp) {
// resp will look like { fc: 15, startAddress: 3, quantity: 6 }
console.log(resp);
}, console.error);
client.writeMultipleRegisters(4, [1, 2, 3, 4]).then(function (resp) {
// resp will look like { fc : 16, startAddress: 4, quantity: 4 }
console.log(resp);
}, console.error);
client.writeMultipleRegisters(4, Buffer.from([0x00, 0x01, 0x00, 0x02, 0x00, 0x03, 0x00, 0x04]).then(function (resp) {
// resp will look like { fc : 16, startAddress: 4, quantity: 4 }
console.log(resp);
}, console.error);
});
client.on('error', function (err) {
console.log(err);
})
// when using arrays as parameters, jsmodbus assumes that all elements inside
// the array are 16bit values. If you want to send a bigger value (32 bit), you need
// to send a buffer, instead of an array:
var buf = Buffer.allocUnsafe(4); // 4 bytes == 32bit
buf.writeInt32BE(77777);
// now you can call any function normally, just sending a buffer instead of an
// array
client.writeMultipleRegisters(4, buf).then(function (resp) {
// resp will look like { fc : 16, startAddress: 4, quantity: 4 }
console.log(resp);
}, console.error);
`
Server example
--------------
javascript
```
var stampit = require('stampit'),
modbus = require('jsmodbus');
var customServer = stampit()
.refs({
'logEnabled' : true,
'port' : 8888,
'responseDelay' : 10, // so we do not fry anything when someone is polling this server
'whiteListIPs' : null, // filter connection only from these IPs (ex. ['127.0.0.1', '192.168.0.1'])
// specify coils, holding and input register here as buffer or leave it for them to be new Buffer(1024)
coils : Buffer.alloc(1024, 0),
holding : Buffer.alloc(1024, 0),
input : Buffer.alloc(1024, 0)
})
.compose(modbus.server.tcp.complete)
.init(function () {
var init = function () {
// get the coils with this.getCoils() [ Buffer(1024) ]
// get the holding register with this.getHolding() [ Buffer(1024) ]
// get the input register with this.getInput() [ Buffer(1024) ]
// listen to requests
this.on('readCoilsRequest', function (start, quantity) {
// do something, this will be executed in sync before the
// read coils request is executed
});
// the write request have pre and post listener
this.on('[pre][post]WriteSingleCoilRequest', function (address, value) {
});
}.bind(this);
init();
});
customServer();
// you can of course always use a standard server like so
var server = modbus.server.tcp.complete({ port : 8888 });
// and interact with the register via the getCoils(), getHolding() and getInput() calls
server.getHolding().writeUInt16BE(123, 1);
// you can filter only certain IP addresses to connect
var server = modbus.server.tcp.complete({ port : 8888, whiteListIPs: ['127.0.0.1', '192.168.0.1'] });