NonStop System Glossary

exception handler
A section of program code to which control is transferred when an exception occurs. The exception
handler then determines what action should be taken.
executable
See object code file.
Executable and Linkable Format (ELF)
A common standard for executable files and object code. On NonStop servers, ELF replaced the
less extensible Common Object File Format (COFF) for native files.
execution mode
The emulated or real instruction set environment in which object code runs. A TNS system has only
one execution mode: TNS mode using TNS compilers and 16-bit TNS instructions. A TNS/R system
has three execution modes: TNS/R native mode using MIPS native compilers and MIPS instructions,
emulated TNS execution in TNS interpreted mode, and emulated TNS execution in TNS accelerated
mode. A TNS/E system also has three execution modes: TNS/E native mode using TNS/E native
compilers and Itanium instructions, emulated TNS execution in TNS interpreted mode, and emulated
TNS execution in TNS accelerated mode.
Expand line-handler process
A process pair that handles incoming and outgoing Expand messages and packets. An Expand
line-handler process handles direct links and also binds to other processes using the Network
Access Method (NAM) interface to support Expand-over-X.25, Expand-over-ServerNet,
Expand-over-TCP/IP, and Expand-over-SNA, and Expand-over-FOX links. See also
Expand-over-ServerNet line-handler process.
Expand network
The NonStop operating system network that extends the concept of fault-tolerant operation to
networks of geographically distributed NonStop systems. If the network is properly designed,
communication paths are constantly available even if a single line failure or component failure
occurs.
Expand node
A system in an Expand network. See also node.
Expand node number
A number in the range 0 through 254, sometimes referred to as the system number, that identifies
a node in an Expand network. Each Expand node number must be unique within the network. See
also ServerNet node number.
Expand-over-ServerNet line
The single line associated with an Expand-over-ServerNet line-handler process. An
Expand-over-ServerNet line has the same name and logical device number as its
Expand-over-ServerNet line-handler process. However, the line does not have the same states as
the line-handler process.
Expand-over-ServerNet line-handler process
An Expand line-handler process that uses the NETNAM protocol to access the Network Access
Method (NAM) interface provided by the ServerNet cluster monitor process, $ZZSCL. The
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