It is possible to interact with a Cognex Mobile terminal from MX Browser using JavaScript on you webpage. There are two events that caught from JavaScript code: "readResultReceived" and "connectionStateChanged".
readResultReceived
The "readResultReceived" event is triggered when the MX device is triggered and "Send event on read result received" is enabled. The read result that is sent to that event has the following format:
{
"readResults" : [
{
"goodRead" : 1,
"readString" : "2112345678900",
"symbology" : 4,
"symbologyString" : "UPC-EAN",
"xml" : "...",
}
],
"subReadResults" : [
],
"xml" : "...",
}
The main readResult object contains three key-value pairs:
- readResults (Array): An array of read result objects that were scanned with an MX Device. If multicode is not enabled on the device, then only one result is in this array. If multicode is configured, then this array contains the main result and all the sub read results.
- subReadResults (Array): An array of read result objects excluding the main result. For single code scanning, this array will be empty.
- xml (String): The raw XML string received by the reader.
To listen for "readResultReceived" event on your website, add the JavaScript event listener like in the example below:
document.addEventListener('readResultReceived', function(barcode_result){
alert(JSON.stringify(barcode_result.detail));
});
connectionStateChanged
The "connectionStateChanged" event is triggered when the MX device changes its connection state and "Send event if connection status changed" is enabled. The attached object has a number representing the new connection state:
0 - Disconnected, the readerDevice is not connected to any remote system.
1 - Connecting, the readerDevice is in the process of establishing a connection to a remote system.
2 - Connected, the readerDevice is connected to a remote system.
3 - Disconnecting, the readerDevice is in the process of disconnecting from a remote system.
4 - Unknown, the readerDevices connection state is unavailable.
To listen for "connectionStateChanged" event on your website, add the following JavaScript event listener:
document.addEventListener('connectionStateChanged', function(connection_state){
alert(JSON.stringify(connection_state.detail));
});
Other possibilities to control MX mobile terminal
The MX Browser allows communication from the web site to the MX Device as well. An object named as "cmbSDK" is available from Javascript after the web page has been loaded. By using this object it is possible to:
- start scanning without having to press a button on the MX mobile terminal
- stop scanning if nothing is being scanned
- trigger userEvent1 and userEvent2 (configurable events on MX mobile terminals)
All you have to do is add the following functions to your web site and call them whenever you need (using timer, on button press, etc.).
function startScanning() {
cmbSDK.triggerStartScan();
}
function stopScanning() {
cmbSDK.triggerStopScan();
}
function triggerUserEvent1() {
cmbSDK.triggerUserEvent1();
}
function triggerUserEvent2() {
cmbSDK.triggerUserEvent2();
}
Disable trigger buttons
MX Browser provides functions that can be called from the source of a web page to disable trigger buttons.
/*
* The following functions configure the trigger buttons of an MX mobile terminal.
* @param state - 0 disable
* - 1 enable triggering
*/
cmbSDK.setLeftTriggerButton(int state);
cmbSDK.setRightTriggerButton(int state);
cmbSDK.setGripTriggerButton(int state);
Caution! Use this function carefully as you can create a state where MX is not responding to your users.
MX Browser sets all of your trigger buttons to enable triggering, when MX Browser is reopened or a new page is loaded.
