Library /sys$common/syshlp/ncphelp.hlb TRIGGER, NODE, PHYSICAL ADDRESS p-address  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 Applies only to nodes on broadcast circuits.  Specifies the physical
 address that the target node currently use to identify itself.   The
 value is the physical address the target node has set for itself or,
 if the target node has not set a physical address, the hardware
 address associated with the target node's device controller.