The TAC Operator Panel will not show the controllers on the network and only displays "No Answer"
Classic and LNS Vista networks
Programmable Xenta controllers only support 2 Operator Panel per device.
To have more operator panels ensure that you have at least one programmable Xenta controller for every two Operator Panels.
Each Xenta controller can only have two Operator Panel connected to it at once.
See Lessons Learned Article #1694 for some other situations that can cause this issue as well.