If you do not get 8/9V from the connector I think you have not set the correct program mode. The 8/9V is switched and is only switched on in the modes when it should be. When using TM-V71 you should set program mode 5.
The RRC do not have to be connected trough routers and switches a cat5 cable is OK, but however the Ip-settings must be ok anyway.
73 de mike