How to: How to override an existing peripheral

Further reading Microsoft Dynamics AX 2012 for Developers [AX 2012] SDK Download

What peripherals can be overridden

We have introduced the ability to override peripherals in POS 2012. The following peripherals types can be overridden once:

ICashDrawer IDualDisplay IKeyLock ILineDisplay ILogOnDevice IMSR IPeripherals IPinPad IPrinter IRadioFrequencyIDScanner IScale IScanner ISignatureCapture

POS will only load the first customization it finds for the above types, so make sure you only include the peripherals you want to customize.

How to customize a POS peripheral

First install the RetailPOS.msi and RetailPOSPlugins.msi

I’ve attached a zip file of the complete project (OnScreenLineDisplay.zip)

Then open the solution file in %USERPROFILE%\Documents\Retail POS Plug-ins\Peripherals\Peripherals.csproj

1. Right click on the project and choose properties

2. Change the Assembly name from Peripherals to your assembly name i.e. OnScreenLineDisplay3. In this example I only want to change the LineDisplay so I remove all the classes from the project

as this allows other assemblies to override those peripherals

4. Rename the LineDisplay.cs to OnScreenLineDisplay.cs5. Remove all the OPOS references as these aren’t need when we display on windows form6. I’ve listed the main changes below for more details please reference the zip file7. Load()

8. Unload()

9. ClearDisplay()

10. DisplayItem() (Required the InternalApplication property add to the class)

11. DisplayTextAt() & AlignedText()

12. Then I copy my OnScreenLineDisplay.dll to %Pos%\Services\Extensions (To copy this dll to multiple installations of POS you can use System Center or similar)

13. The when you run POS you see the following