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| 1 | +#!/usr/bin/env python |
| 2 | +# -*- coding: utf-8 -*- |
| 3 | + |
| 4 | +## Copyright (C) 2019 David Miguel Susano Pinto <david.pinto@bioch.ox.ac.uk> |
| 5 | +## |
| 6 | +## Microscope is free software: you can redistribute it and/or modify |
| 7 | +## it under the terms of the GNU General Public License as published by |
| 8 | +## the Free Software Foundation, either version 3 of the License, or |
| 9 | +## (at your option) any later version. |
| 10 | +## |
| 11 | +## Microscope is distributed in the hope that it will be useful, |
| 12 | +## but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | +## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | +## GNU General Public License for more details. |
| 15 | +## |
| 16 | +## You should have received a copy of the GNU General Public License |
| 17 | +## along with Microscope. If not, see <http://www.gnu.org/licenses/>. |
| 18 | + |
| 19 | +"""Prior controller. |
| 20 | +""" |
| 21 | + |
| 22 | +import contextlib |
| 23 | +import threading |
| 24 | +import typing |
| 25 | + |
| 26 | +import serial |
| 27 | + |
| 28 | +import microscope.devices |
| 29 | + |
| 30 | + |
| 31 | +class _ProScanIIIConnection: |
| 32 | + """Connection to a Prior ProScanIII and wrapper to its commands. |
| 33 | +
|
| 34 | + Devices that are controlled by the same controller should share |
| 35 | + the same connection instance to ensure correct synchronization of |
| 36 | + communications from different threads. This ensures that commands |
| 37 | + for different devices, or replies from different devices, don't |
| 38 | + get entangled. |
| 39 | +
|
| 40 | + This class also implements the logic to parse and validate |
| 41 | + commands so it can be shared between multiple devices. |
| 42 | +
|
| 43 | + """ |
| 44 | + def __init__(self, port: str, baudrate: int, timeout: float) -> None: |
| 45 | + # From the technical datasheet: 8 bit word 1 stop bit, no |
| 46 | + # parity no handshake, baudrate options of 9600, 19200, 38400, |
| 47 | + # 57600 and 115200. |
| 48 | + self._serial = serial.Serial(port=port, baudrate=baudrate, |
| 49 | + timeout=timeout, bytesize=serial.EIGHTBITS, |
| 50 | + stopbits=serial.STOPBITS_ONE, |
| 51 | + parity=serial.PARITY_NONE, xonxoff=False, |
| 52 | + rtscts=False, dsrdtr=False) |
| 53 | + self._lock = threading.RLock() |
| 54 | + |
| 55 | + with self._lock: |
| 56 | + # We do not use the general get_description() because if |
| 57 | + # this is not a ProScan device it would never reach the |
| 58 | + # '\rEND\r' that signals the end of the description. |
| 59 | + self.command(b'?') |
| 60 | + answer = self.readline() |
| 61 | + if answer != b'PROSCAN INFORMATION\r': |
| 62 | + self.read_until_timeout() |
| 63 | + raise RuntimeError("Not a ProScanIII device: '?' returned '%s'" |
| 64 | + % answer.decode()) |
| 65 | + # A description ends with END on its own line. |
| 66 | + line = self._serial.read_until(b'\rEND\r') |
| 67 | + if not line.endswith(b'\rEND\r'): |
| 68 | + raise RuntimeError("Failed to clear description") |
| 69 | + |
| 70 | + |
| 71 | + def command(self, command: bytes) -> None: |
| 72 | + """Send command to device.""" |
| 73 | + with self._lock: |
| 74 | + self._serial.write(command + b'\r') |
| 75 | + |
| 76 | + def readline(self) -> bytes: |
| 77 | + """Read a line from the device connection.""" |
| 78 | + with self._lock: |
| 79 | + return self._serial.read_until(b'\r') |
| 80 | + |
| 81 | + def read_until_timeout(self) -> None: |
| 82 | + """Read until timeout; used to clean buffer if in an unknown state.""" |
| 83 | + with self._lock: |
| 84 | + self._serial.flushInput() |
| 85 | + while len(self._serial.readline()) != 0: |
| 86 | + continue |
| 87 | + |
| 88 | + def _command_and_validate(self, command: bytes, expected: bytes) -> None: |
| 89 | + """Send command and raise exception if answer is unexpected""" |
| 90 | + with self._lock: |
| 91 | + answer = self.get_command(command) |
| 92 | + if answer != expected: |
| 93 | + self.read_until_timeout() |
| 94 | + raise RuntimeError("command '%s' failed (got '%s')" |
| 95 | + % (command.decode(), answer.decode())) |
| 96 | + |
| 97 | + def get_command(self, command: bytes) -> bytes: |
| 98 | + """Send get command and return the answer.""" |
| 99 | + with self._lock: |
| 100 | + self.command(command) |
| 101 | + return self.readline() |
| 102 | + |
| 103 | + def move_command(self, command: bytes) -> None: |
| 104 | + """Send a move command and check return value.""" |
| 105 | + # Movement commands respond with an R at the end of move. |
| 106 | + # Once a movement command is issued the application should |
| 107 | + # wait until the end of move R response is received before |
| 108 | + # sending any further commands. |
| 109 | + # TODO: this times 10 is a bit arbitrary. |
| 110 | + with self.changed_timeout(10 * self._serial.timeout): |
| 111 | + self._command_and_validate(command, b'R\r') |
| 112 | + |
| 113 | + def set_command(self, command: bytes) -> None: |
| 114 | + """Send a set command and check return value.""" |
| 115 | + # Property type commands that set certain status respond with |
| 116 | + # zero. They respond with a zero even if there are invalid |
| 117 | + # arguments in the command. |
| 118 | + self._command_and_validate(command, b'0\r') |
| 119 | + |
| 120 | + def get_description(self, command: bytes) -> bytes: |
| 121 | + """Send a get description command and return it.""" |
| 122 | + with self._lock: |
| 123 | + self.command(command) |
| 124 | + return self._serial.read_until(b'\rEND\r') |
| 125 | + |
| 126 | + |
| 127 | + @contextlib.contextmanager |
| 128 | + def changed_timeout(self, new_timeout: float): |
| 129 | + previous = self._serial.timeout |
| 130 | + try: |
| 131 | + self._serial.timeout = new_timeout |
| 132 | + yield |
| 133 | + finally: |
| 134 | + self._serial.timeout = previous |
| 135 | + |
| 136 | + |
| 137 | + def assert_filterwheel_number(self, number: int) -> None: |
| 138 | + assert number > 0 and number < 4 |
| 139 | + |
| 140 | + |
| 141 | + def _has_thing(self, command: bytes, expected_start: bytes) -> bool: |
| 142 | + # Use the commands that returns a description string to find |
| 143 | + # whether a specific device is connected. |
| 144 | + with self._lock: |
| 145 | + description = self.get_description(command) |
| 146 | + if not description.startswith(expected_start): |
| 147 | + self.read_until_timeout() |
| 148 | + raise RuntimeError("Failed to get description '%s' (got '%s')" |
| 149 | + % (command.decode(), description.decode())) |
| 150 | + return not description.startswith(expected_start + b'NONE\r') |
| 151 | + |
| 152 | + |
| 153 | + def has_filterwheel(self, number: int) -> bool: |
| 154 | + self.assert_filterwheel_number(number) |
| 155 | + # We use the 'FILTER w' command to check if there's a filter |
| 156 | + # wheel instead of the '?' command. The reason is that the |
| 157 | + # third filter wheel, named "A AXIS" on the controller box and |
| 158 | + # "FOURTH" on the output of the '?' command, can be used for |
| 159 | + # non filter wheels. We hope that 'FILTER 3' will fail |
| 160 | + # properly if what is connected to "A AXIS" is not a filter |
| 161 | + # wheel. |
| 162 | + return self._has_thing(b'FILTER %d' % number, b'FILTER_%d = ' % number) |
| 163 | + |
| 164 | + |
| 165 | + def get_n_filter_positions(self, number: int) -> int: |
| 166 | + self.assert_filterwheel_number(number) |
| 167 | + answer = self.get_command(b'FPW %d' % number) |
| 168 | + return int(answer) |
| 169 | + |
| 170 | + def get_filter_position(self, number: int) -> int: |
| 171 | + self.assert_filterwheel_number(number) |
| 172 | + answer = self.get_command(b'7 %d F' % number) |
| 173 | + return int(answer) |
| 174 | + |
| 175 | + def set_filter_position(self, number: int, pos: int) -> None: |
| 176 | + self.assert_filterwheel_number(number) |
| 177 | + self.move_command(b'7 %d %d' % (number, pos)) |
| 178 | + |
| 179 | + |
| 180 | +class ProScanIII(microscope.devices.ControllerDevice): |
| 181 | + """Prior ProScanIII controller. |
| 182 | +
|
| 183 | + The controlled devices have the following labels: |
| 184 | +
|
| 185 | + `filter 1` |
| 186 | + Filter wheel connected to connector labelled "FILTER 1". |
| 187 | + `filter 2` |
| 188 | + Filter wheel connected to connector labelled "FILTER 1". |
| 189 | + `filter 3` |
| 190 | + Filter wheel connected to connector labelled "A AXIS". |
| 191 | +
|
| 192 | + .. note:: |
| 193 | +
|
| 194 | + The Prior ProScanIII can control up to three filter wheels. |
| 195 | + However, a filter position may have a different number |
| 196 | + dependening on which connector it is. For example, using an 8 |
| 197 | + position filter wheel, what is position 1 on the filter 1 and 2 |
| 198 | + connectors, is position 4 when on the A axis (filter 3) |
| 199 | + connector. |
| 200 | +
|
| 201 | + """ |
| 202 | + def __init__(self, port: str, baudrate: int = 9600, timeout: float = 0.5, |
| 203 | + **kwargs) -> None: |
| 204 | + super().__init__(**kwargs) |
| 205 | + self._conn = _ProScanIIIConnection(port, baudrate, timeout) |
| 206 | + self._devices = {} # type: typing.Mapping[str, microscope.devices.Device] |
| 207 | + |
| 208 | + # Can have up to three filter wheels, numbered 1 to 3. |
| 209 | + for number in range(1, 4): |
| 210 | + if self._conn.has_filterwheel(number): |
| 211 | + key = 'filter %d' % number |
| 212 | + self._devices[key] = _ProScanIIIFilterWheel(self._conn, number) |
| 213 | + |
| 214 | + @property |
| 215 | + def devices(self) -> typing.Mapping[str, microscope.devices.Device]: |
| 216 | + return self._devices |
| 217 | + |
| 218 | + |
| 219 | +class _ProScanIIIFilterWheel(microscope.devices.FilterWheelBase): |
| 220 | + def __init__(self, connection: _ProScanIIIConnection, number: int) -> None: |
| 221 | + super().__init__() |
| 222 | + self._conn = connection |
| 223 | + self._number = number |
| 224 | + self._positions = self._conn.get_n_filter_positions(self._number) |
| 225 | + |
| 226 | + def get_position(self) -> int: |
| 227 | + return self._conn.get_filter_position(self._number) |
| 228 | + |
| 229 | + def set_position(self, position: int) -> None: |
| 230 | + self._conn.set_filter_position(self._number, position) |
| 231 | + |
| 232 | + def _on_shutdown(self) -> None: |
| 233 | + super()._on_shutdown() |
| 234 | + |
| 235 | + def initialize(self) -> None: |
| 236 | + super().initialize() |
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