frappy/doc/source/server.rst

Server

Configuration

The configuration code consists of a Node() <node configuration> section, and one Mod() <mod configuration> section per SECoP module.

The Node section contains a globally unique ID of the SEC node, a description of the SEC node and the server interface uri. Example:

Node('globally.valid.identifier',
     'a description of the SEC node',
     interface = 'tcp://5000')

For the interface scheme currently only tcp is supported. When the TCP port is given as an argument of the server start script, interface is not needed or ignored. The main information is the port number, in this example 5000.

All other Mod() <mod configuration> sections define the SECoP modules. Mandatory fields are name, cls and description. cls is a path to the Python class from where the module is instantiated, separated with dots. In the following example the class HeLevel used by the helevel module can be found in the PSI facility subdirectory frappy_psi in the python module file ccu4.py:

Mod('helevel',
    'frappy_psi.ccu4.HeLevel',
    'this is the He level sensor of the main reservoir',
    empty_length = Param(380, export=False),
    full = Param(0, export=False))

It is highly recommended to use all lower case for the module name, as SECoP names have to be unique despite of casing. In addition, parameters, properties and parameter properties might be initialized in this section. In the above example empty_length and full_length are parameters, the resistivity of the He Level sensor at the end of the ranges. In addition, we alter the default property export of theses parameters, as we do not want to expose these parameters to the SECoP interface.

Starting

The Frappy server can be started via the bin/frappy-server script.

usage: bin/frappy-server [-h] [-v | -q] [-d] [-t] [-p port] [-c cfgfiles] name

Manage a Frappy server

positional arguments:

name name of the instance. Uses <config path>/name_cfg.py for configuration

optional arguments:

-c, --cfgfiles

config files to be used. Comma separated list. defaults to <name> when omitted

-p, --port

server port (default: take from cfg file)

-h, --help

show this help message and exit

-v, --verbose

output lots of diagnostic information

-q, --quiet

suppress non-error messages

-d, --daemonize

run as daemon

-t, --test

check cfg files only