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I've implemented modbus client request/responses 1-6,15,16 #4

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I've implemented modbus client request/responses 1-6,15,16 #4

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b28340b
Implemented function code 16 (Write Multiple Registers)
Jun 6, 2013
229b363
Client request/responses 1-6,15,16 are now fully implemented
Jun 9, 2013
7601c62
Fixed package.json syntax
Jun 9, 2013
d887b31
Fixed WRITE_MULTIPLE_COILS request bit order
Jun 9, 2013
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127 changes: 111 additions & 16 deletions client.js
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Original file line number Diff line number Diff line change
Expand Up @@ -4,6 +4,7 @@ var Binary = require('bufferlist/binary').Binary;
var modbus = require('./modbus-stack');
var netStream = require('net').Stream;
var FUNCTION_CODES = modbus.FUNCTION_CODES;
var BitArray = require('node-bitarray');

/* TCP MODBUS Client interface, as it's the most usual use-case. */
function Client () {
Expand Down Expand Up @@ -54,32 +55,126 @@ Client.REQUESTS = {
5: function(address, value) {
if (typeof value !== 'boolean') throw new Error('"Write Single Coil" expects a \'boolean\' value');
return putTwoWord16be(address, value ? 0xff00 : 0x0000);
},
// WRITE_SINGLE_REGISTER
6: putTwoWord16be,

// WRITE_MULTIPLE_COILS
15: function(address, values) {
if(values.length < 1 || values.length > 1968) {
throw new Error('"Write Multiple Coils" expects 1 to 1968 registers');
}

values.map(
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@TooTallNate TooTallNate Apr 27, 2015

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You're not assigning the result of map() to anything here!

function(val) {
if (typeof val !== 'boolean') throw new Error('"Write Multiple Coils" expects \'boolean\' values');
return val ? 1 : 0;
}
)

request = Put()
.word16be(address)
.word16be(values.length)
.word8(Math.ceil(values.length/8));

// We have to reverse each 8 bits
while(values.length > 0) {
request.put(BitArray.toBuffer(
values.splice(0,8)
.reverse() // The LSB of the first data byte contains the output addressed in the query.
));
}

return request.buffer();
},

// WRITE_MULTIPLE_REGISTERS
16: function(address, values) {
if(values.length < 1 || values.length > 123) {
throw new Error('"Write Multiple Registers" expects 1 to 123 registers');
}

request = Put()
.word16be(address)
.word16be(values.length)
.word8(values.length*2);

for(var i=0; i<values.length; i++) {
request.word16be(values[i]);
}

return request.buffer();
}
};

Client.RESPONSES = {
// READ_INPUT_REGISTERS
4: function(bufferlist) {
var rtn = [];
function readBitArray(bufferlist) {
var binary = Binary(bufferlist)
.getWord8('byteCount')
.end();

var rtn = [];
for(var i=0, l=binary.vars.byteCount; i<l; i++) {
binary.getBuffer("oneByteBuffer", 1).end();
rtn = rtn.concat(
BitArray.fromBuffer(binary.vars.oneByteBuffer)
.reverse() // The LSB of the first data byte contains the output addressed in the query.
.map(function(val) { return val==1 ? true : false})
);
}

rtn.byteCount = binary.vars.byteCount;
return rtn;
}

function read16beArray(bufferlist) {
var binary = Binary(bufferlist)
.getWord8('byteLength').end();
rtn.byteLength = binary.vars.byteLength;
for (var i=0, l=binary.vars.byteLength/2; i<l; i++) {
.getWord8('byteCount')
.end();

var rtn = [];
rtn.byteCount = binary.vars.byteCount;
for (var i=0, l=binary.vars.byteCount/2; i<l; i++) {
binary.getWord16be("val");
rtn.push(binary.end().vars.val);
}
return rtn;
},
}

function readAddressQuantity(bufferlist) {
var binary = Binary(bufferlist)
.getWord16be("address")
.getWord16be("quantity")
.end();
return binary.vars;
}

function readAddressValue(bufferlist) {
var binary = Binary(bufferlist)
.getWord16be("address")
.getWord16be("value")
.end();
return binary.vars;
}

Client.RESPONSES = {
// READ_COILS
1: readBitArray,
// READ_DISCRETE_INPUTS,
2: readBitArray,
// READ_HOLDING_REGISTERS
3: read16beArray,
// READ_INPUT_REGISTERS
4: read16beArray,
// WRITE_SINGLE_COIL
5: function(bufferlist) {
var rtn = [];
var binary = Binary(bufferlist)
.getWord8('byteLength').end();
rtn.byteLength = binary.vars.byteLength;
for (var i=0, l=binary.vars.byteLength/2; i<l; i++) {
binary.getWord16be("val");
rtn.push(binary.end().vars.val);
}
var rtn = readAddressValue(bufferlist);
rtn.value = rtn.value ? true : false;
return rtn;
},
// WRITE_SINGLE_REGISTER
6: readAddressValue,
// WRITE_MULTIPLE_COILS
15: readAddressQuantity,
// WRITE_MULTIPLE_REGISTERS
16: readAddressQuantity,
};
5 changes: 3 additions & 2 deletions package.json
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Original file line number Diff line number Diff line change
Expand Up @@ -11,7 +11,8 @@
"dependencies": {
"stream-stack": ">= 1.0.1",
"bufferlist": ">= 0.0.6",
"put": "*"
"put": "*",
"node-bitarray": ">= 0.0.2"
},
"devDependencies": {
"colors": ">= 0.3.0",
Expand All @@ -28,4 +29,4 @@
"files": [
""
]
}
}
1 change: 1 addition & 0 deletions server.js
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Original file line number Diff line number Diff line change
Expand Up @@ -5,6 +5,7 @@ var Binary = require('bufferlist/binary').Binary;
var modbus = require('./modbus-stack');
var FUNCTION_CODES = modbus.FUNCTION_CODES;


/* Streamlined TCP MODBUS server class. Can be used to respond to MODBUS requests
* from TCP clients. `handlers` can be a function which is invoked for every
* "request" event, or an Object with keys being the Function Codes your server
Expand Down