[POS] Attempting to automatically open a cashdrawer - .net variable has not been instantianed

Hello Dynamics community!

My first steps into Nav 2016 and I'm getting an error.
I'm connecting a PC
HP RP7800 Retail System
with a cashdrawer
HP Standard Duty Cash Drawer (QT457AA)

I'm connecting the cashdrawer directly (without a receipt printer) and use a "RJ45 from drawer to RJ12 to the PC" cable.

POS Drivers from here and POS for .NET from here installed.

In the both packs there are test tools with which I succeed at opening the cashdrawer automatically.
The tools look somewhat like this on the 8 site from this PDF from the OPOS drivers pack
https://drive.google.com/open?id=0B5eop_-6tY07UGgzNG5RVXRtS2c

I have referenced a few DLLs from the .NET for POS Pack and activated the RunOnClient property on them.
My code in NAV

//PosDevice := PosExplorer.PosExplorer;
//PosCommon.
 //CashDrawer.
//PosCommon.Open();
// PosDevice.
// PosDrawer.OpenDrawer();
// PoSDrawer := PoSDrawer.OpenDrawer();
//PosExplorer. OpenDrawer();

 KassenFunktionen := KassenKlasse.OPOSCashDrawerClass;
 KassenFunktionen.Open('HP_CashDrawerPort-1');
 KassenFunktionen.DeviceEnabled := TRUE;
 KassenFunktionen.ClaimDevice(1000);
 KassenFunktionen.OpenDrawer;

PosDeviceCollection := PosExplorer.GetDevices('CashDrawer');
MESSAGE(PosDeviceCollection.ToString);
PosDeviceInfo := PosDeviceCollection.Item(1);
MESSAGE(PosDeviceInfo.ToString);

 PosDeviceInfo := PosExplorer.GetDevice('CashDrawer','HP_CashDrawerPort-1');
  check := PosDeviceInfo.IsDefault;
  MESSAGE(FORMAT(check));

 PosCommon := PosExplorer.CreateInstance(PosDeviceInfo);
 PosCommon.Open;
 MESSAGE(PosDevice.ToString);

 PoSDrawer.Open;
 PoSDrawer.Claim(10000);
 PoSDrawer.DeviceEnabled := TRUE;
 PoSDrawer.OpenDrawer;
 PoSDrawer.DeviceEnabled := FALSE;
 PoSDrawer.Release;
 PoSDrawer.Close 

//CashDrawer.Open;
//CashDrawer.Claim(10000);
//CashDrawer.DeviceEnabled := TRUE;
//CashDrawer.OpenDrawer;  
//CashDrawer.DeviceEnabled := FALSE;
//CashDrawer.Release;
//CashDrawer.Close;
// 
//

I just need a piece of code that opens the cashdrawer, the info checks etc arent essential.
Sorry, that there are too many comments. I copied the code as fast as I could and replicated some of it from memory. Didn't want to delete the wrong ones because I'm a newbie. No matter what I tried to change with the code it showed me errors.

The error looks like this:)

I really have no idea
This doesnt help

I will try to answer everything as soon as I get to the code again.
Thanks in advance for the time wasted on me.