pysmlib 3.0.0

Python Finite State Machines for EPICS

pysmlib

Python Finite State Machines for EPICS

Developers: Damiano Bortolato - Davide Marcato @ Laboratori Nazionali di Legnaro - INFN

Main Repository: https://github.com/darcato/pysmlib

Full documentation: https://darcato.github.io/pysmlib/docs/html/

Main features

• Easy to use and fast development of complex event based fsm - just code the states!
• Full EPICS Channel Access integration via PyEpics.
• High expandability as provided by all the libraries of Python.
• Integrated configurable logging systems.
• Convenient methods to access all the information on I/O.
• Timers can be used to execute actions after a time delay.
• Integrated watchdog logic.
• Multi-threading: each fsm is executed on a different thread, sharing I/O.
• Convenient loader to launch a daemon with multiple fsm.
• Possibility to apply a configurable naming convention on I/O.

Installation

To install simply run:

pip install pysmlib

or download the latest release/sources from github, unpack it and run:

cd pysmlib
pip install .

Dependencies

Requires Python 3.6+. Pyepics is required and automatically installed by pip. Sphinx and its theme "Read the Docs" are required to build the documentation.

Example

#! /usr/bin/python
from smlib import fsmBase, loader

# FSM definition
class exampleFsm(fsmBase):
    def __init__(self, name, *args, **kwargs):
        super(exampleFsm, self).__init__(name, **kwargs)

        self.counter = self.connect("testcounter") # connect to PV "testcounter"
        self.mirror = self.connect("testmirror")
        self.enable = self.connect("testenable")

        self.gotoState('idle')

    # idle state
    def idle_eval(self):
        if self.enable.rising():
            self.gotoState("mirroring")

    # mirroring state
    def mirroring_eval(self):
        if self.enable.falling():
            self.gotoState("idle")
        elif self.counter.changing():
            readValue = self.counter.val()
            self.mirror.put(readValue)

# Main
if __name__ == '__main__':
    # load the fsm
    loader.load(exampleFsm, "myFirstFsm")

    # start execution
    loader.start()