Is "node 0" and "local" referring to the same instrument in the mapping menus?

 "Node 0" can be the node with the communications card or another location on the string of node addresses.  In mapping the word local refers to the controller being mapped.

All HI 3000 Series units (which includes the HI 3010, and the HI 3030) have the capability to link multiple units together via their Control Link (Ethernet TCP/IP) connection. This will allow up to 16 other units to connect to the "Local" unit. (peer-to-peer)

The "Local" unit is the one being configured and is usually the node with the communication card. The Node IP addresses for the other Ethernet TCP/IP network linked units can be entered via their front panel Ethernet setup or through their browser. The Local controller (IP address) would be listed on all the other Nodes on that link setup. This allows the user to enter up to 16 addresses for the other units, numbered Node 0 through Node 15. This gives a total of 17 units that can be "online", to the "Local" controller, communicating with Nodes 0 - 15.

This communications can be a combination of shared resources like relays and inputs, or a shared communication path to the PLC or DCS.