Launching Parallel Android Devices in Robot Framework

I am using Robot Framework + Appium to automate Android Mobile apps and it works great with one physical device connected.

I have a script to run in parallel for multiple devices. I have googled and only found one helpful forum. http://testnblog.com/executing-robot-test-cases-in-parallel-on-2-android-devices-through-appium/

When I followed the steps above, I was able to start multiple instances of Appium, but when I call the same from Robot Framework as mentioned in the forum, I get below error:

WebDriverException: Message: A new session could not be created. (Original error
: Command failed: C:\Windows\system32\cmd.exe /s /c "D:\adb\adt-bundle-windows-x
86_64-20130917\sdk\platform-tools\adb.exe shell "getprop persist.sys.language""
error: more than one device/emulator)

      

        
        
        
      

    

Can anyone help me out or suggest a solution if you have achieved the same using the Robot framework