OPC-server Kepware and Zenon 6.51

OPC-server Kepware and Zenon 6.51

Hello,
I have some problems with communication of Zenon and Kepware on different computers. I have the first PC with OPC-server and the second PC with Zenon. I made test channel with simulator driver in Kepware. In Zenon I made test variable with OPC Client V20 driver. On runtime-mode in place of the variable value I see empty cell with blue square in the right corner (notice: Not updated). What is this? And how can I decide the issue?
P.S. I made variable and test channel on another PC with Zenon and Kepware, and it works there.

This is a migrated post! Originally posted on 12.08.2011 by user croc. Please be aware that information can be outdated.