To configure the connection:
Before you can access a Grapevine Node in JMRI, you have to define it to the program. You can do this either from the Preferences window (under Edit in the main menu, click "Configure Nodes") or using the Configure Nodes tool in the Grapevine menu.
Grapevine Systems Names start with a system letter of "G", optionally followed by an
integer to form a unique System Prefix. After the prefix, there's a type letter, then a node number and a pin
number.
Naming and input/output connectors are described on a separate
page.
If desired, check "Additional Conection Settings" and select an option for "Auto-initialize" to have Simulator generate automatic replies from node inputs/outputs:
The Grapevine menu gives access to: