I've built a simple VB.NET native library to communicate with KUKAVARPROXY.
It builds the TCP packet to make the read/write requests to KUKAVARPROXY.exe without using JOpenShowVar.
Read/write time is around 7-8ms.
KUKAVARPROXY.exe is included in the archive you are downloading, just unzip it and run it on the robot controller, you may also put it into the windows startup folder, to ,make it start when robot is tuned on.
Also, modify KUKA firewall to allow port 7000 TCP.
Attached you will find the visual studio 2012 project with a demo application
UPDATE March 2020:
- some bugs in the TCP communication corrected
- have a look at https://github.com/ImtsSrl/KUKAVARPROXY for the KUKAVARPROXY program.