How to solve a checksum mismatch error using the XBee API in Node.js

Question

Node.js (on Ubuntu) uses the XBee API library as the ZigBee coordinator API to send data to XBee as ZigBee router AT every one minute. It's fine for 10 minutes, but after that it reports an error:

Error: Checksum Mismatch

How do I solve this problem?

var util = require('util');
var SerialPort = require('serialport').SerialPort;
var xbee_api = require('xbee-api');

var C = xbee_api.constants;

var xbeeAPI = new xbee_api.XBeeAPI({
    api_mode: 1
});

var serialport = new SerialPort("COM19", {
    baudrate: 57600,
    parser: xbeeAPI.rawParser()
});

serialport.on("open", function() {
    var frame_obj = {
        type: 0x10, // xbee_api.constants.FRAME_TYPE.ZIGBEE_TRANSMIT_REQUEST
        id: 0x01, // Optional, nextFrameId() is called per default
        destination64: "0013a200400a0127",
        destination16: "fffe", // Optional, "fffe" is default
        broadcastRadius: 0x00, // Optional, 0x00 is default
        options: 0x00, // Optional, 0x00 is default
        data: "TxData0A" // Can either be a string or byte array.
    };
    serialport.write(xbeeAPI.buildFrame(frame_obj));
});

// All frames parsed by the XBee will be emitted here
xbeeAPI.on("frame_object", function(frame) {
    console.log(">>", frame);
});

Answer 1

Is it possible to print (to stdout) a hex dump of each frame sent, and the checksum frame so you can see which frame is flagged with the error? Can you monitor the serial line in some way to see what you're actually sending? How is the XBee module connected to the host? Does it use a long serial cable that could be encountering noise?

Do you always get the error after 10 packets, or does it vary? If you change the baud rate to 9600 or 115200, does the error rate stay the same, become more frequent or go away?

You probably shouldn't hard code the frame ID to be the same on every packet -- it could be contributing to the problem, and you won't know which frame had the checksum error, if they're all using the same ID. The error frame includes a field for the frame ID that generated the error.

Answer 2

This happens in case of a mismatch between your code configuration and the xbee module configuration, just be sure if you have configured the same API mode in both cases,then you must call the serialport parser and pass the data to the xbee parser :

serialport.on('data', function (data) { xbeeAPI.parseRaw(data); });

then you can deal with the received frame the way you want

xbeeAPI.on("frame_object", function(frame) { ... };

Answer 3

I've got the same problem when using the "ND" AT command to scan the network, the devices should send a frame that contain the ID, MAC 64 and 16 etc separately, in this case the problem appear when receiving all devices answers at the same time, specially when using more than two devices or routers, buffers will be damaged and the xbee-api parser couldn't work properly. So you need to used a higher baud rate. The problem disappear using API 2 mode with the baud rate 57600(option 6) or 115200(option 7), it work fine for me.

Answer 4

I was having the same issue as you. The problem in my case was that in the configuration of the XBee coordinator module, I had set the API mode (Parameter AP) to be 2 (API with escaping). In the node.js code I set the API mode to be 1, as you have in your code. The API mode must be set to be the same in both or the parser will throw an error, so the fix is to set the change the code to be API 2 or change the configuration of the module to be API 1.

I'm a bit late I know but thought I'd answer in case anyone else is having the same trouble that I was!