""" .. module:: laser :platform: unix :synopsis: This module is for communicating with the laser. .. codeauthor:: Eric Coughlin This is a module that communicates with the ESKPLA laser in the lab via RS232 serial port. """ import serial import argparse import string import numpy as np import logging class LaserSerialInterface: """ This class is for communicating with the laser through the RS232 serial interface. """ def __init__(self, loop=True, port='/dev/ttyUSB.LASER'): self.state = None self.error = None self.states = {'[PC:READY=0\NL]': ['ready', 'The device is ready'],'[PC:BUSY=0\NL]': ['busy', 'The device is busy'], '[PC:OFF=0\NL]': ['off', 'The device is off'], '[PC:READY=2048\NL]': ['ready', 'The device is ready but with cooling error.'], '': ['off', 'The device is off']} self.commands = {'say_state_msg': '[NL:SAY\PC]'} self.responses = {'[NL:What\PC]': 'Unrecognized string', '[NL:Ignored\PC]': 'Unrecognized command'} if loop: self.serial = serial.serial_for_url('loop://') else: try: self.serial = serial.Serial(port=port, baudrate=19200, timeout=2) self.status = "connected" self.check_state() self.check_wavelength() except Exception as e: print(e) self.status = "not connected" self.state = "not connected" def test_state(self): """ This is a method for testing the state of the laser in a loop-back environment. :return: """ if self.status != "not connected": responses = ['[PC:OFF=0\NL]', '[PC:BUSY=0\NL]', '[PC:BUSY=0\NL]', '[PC:READY=0\NL]'] for response in responses: say_state_msg = self.commands['say_state_msg'] self.serial.write(say_state_msg) if response in self.states: self.state = self.states[response][0] print(self.states[response][1]) else: pass def check_state(self): """ This method checks the status of the laser and then sets the state of the laser inside of the class. :return: """ if self.status != "not connected" and self.status != "off": say_state_msg = self.commands['say_state_msg'] self.serial.write(say_state_msg) response = self.serial.read(size=25) print('check_state response: {}'.format(response)) if response == "": self.state = "off" self.status = "off" logging.info("The laser is off") return if response in self.states: self.state = self.states[response][0] print(self.states[response][1]) else: print(response) logging.info("Not found.") else: pass def get_ready_state(self): """ This method calls the :py:meth:`check_state` until a ready state is set by the class. :return: """ if self.status != "not connected" and self.status != "off": while self.state != 'ready' and self.state != 'off' and self.state != 'not connected': logging.info("checking state...") self.check_state() else: pass def change_wavelength(self, wavelength): """ This method changes the wavelength of the laser. :param wavelength: This is the value of the wavelength to be set. Units are in nanometers and limits are 355nm to 2300 nm. :return: """ if self.status != "not connected" and self.status != "off": self.get_ready_state() if self.state != "off" and self.state != "not connected": wavelength_change_msg = '[W0/S{0}]'.format(str(wavelength)) if wavelength < 350 or wavelength > 1400: raise Exception("Wavelength limits exceeded bounds") else: self.serial.write(wavelength_change_msg) check_response = self.check_wavelength(comparison=True) if int(wavelength) == check_response: logging.info("Wavelength set correctly") else: logging.info("Something went wrong") elif self.state == "off": raise Exception('The laser is turned off') elif self.state == "not connected": raise Exception('The laser is not connected properly') else: pass def check_wavelength(self, comparison=False): """ This method checks the wavelength of the laser and either prints the result or checks that the wavelength is set correctly. :param comparison: This is a flag as to whether wavelength values will be compared or not. :return: """ if self.status != "not connected" and self.status != "off": if self.state != "not connected": wavelength_check_msg = '[W0/?]' self.serial.write(wavelength_check_msg) response = self.serial.read(size=25) if response == "": return 0 logging.info(response) if comparison: wavelength = self.parse_wavelength(response) self.wavelength = wavelength return wavelength else: wavelength = self.parse_wavelength(response) self.wavelength = wavelength logging.info(wavelength) else: raise Exception('The laser is not connected properly') else: self.wavelength = None def parse_wavelength(self,msg='[MS:W0/S520\NL]'): """ This method parses through the message to get back the value of the wavelength .. note:: A potential limitation is parsing through float messages. :param msg: This is the message to parse. :return: returns the value of the wavelength as parsed. """ if self.status != "not connected" and self.status != "off": msg_parse = msg remove_chars = [] for char in string.letters: remove_chars.append(char) for char in string.punctuation: remove_chars.append(char) split_msg = msg_parse.translate(None, ''.join(remove_chars)) split_msg = split_msg[1:] return int(split_msg) else: pass def loop_change_wavelength(self, min, max,diagnostic): """ This method loops through the meth:`change wavelength` method starting from min and ending at max. :param min: The starting wavelength :param max: the ending wavelength :param diagnostic: whether this loop is going to wait for user input to continue :return: """ if self.status != "not connected" and self.status != "not connected": np_array = np.arange(min,max+1) for item in np_array: try: self.change_wavelength(item) except Exception as e: logging.exception(e) break if not diagnostic: raw_input("Press Enter to continue") print("done.") else: pass def create_parser(): parser = argparse.ArgumentParser(description='Program to change the wavelength of the laser using rs232 interface.') parser.add_argument('wavelength', nargs=1, help='This is for setting the value of the wavelength of the laser.', type=float) return parser def main(wavelength,port): """ This creates a command line and arguments for the script. :return: None """ laser_interface = LaserSerialInterface(loop=False,port=port) #laser_interface.loop_change_wavelength(500, 520, False) laser_interface.change_wavelength(wavelength) if __name__ == '__main__': parser = create_parser() args = parser.parse_args() wavelength = np.float(args.wavelength[0]) main(wavelength,port='/dev/ttyUSB2')