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or a Client Module. Client Modules only use the functionality provided by the
LabRAD system, while Server Modules also provide new functionality that other
Server and Client Modules can use. This distinction allows the LabRAD Manager
to maintain an index of all available Server Modules to quickly give an overview of
the available functionality. Each Server Module then registers so-called “Settings”
with the Manager that provide the interface to the Server’s functionality. Both
the Servers and their Settings have a human-readable name for easy identification
as well as a numeric ID that allows for reduced traffic and quicker Request routing.
When registering a Setting with the Manager, the Server also has to provide
a help text and specifications about which types of data this Setting requires and
returns. This information is made available by the Manager to provide a one-stop
source for basic documentation of all features of the system.
Since Settings are addressed by name and can register multiple acceptable
data types it is easily possible to extend the collection of Settings or the functionality
of individual Settings provided by a Server without breaking backwards
compatibility. Most modern programming languages can achieve this same result
through things like overloading of functions or polymorphic SubVIs, but this ability
is usually seen as a fringe feature and does not get much attention. Therefore,
casual programmers like physicists usually either don’t know about it or don’t feel
comfortable using it.
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