frappy/frappy_psi/phytron.py
l_samenv 1ce43a567b fixes in sea cfg files
- json_file must be a string, not a list
- rel_path is no longer to be converted to a list
2023-05-10 16:36:32 +02:00

255 lines
10 KiB
Python

# -*- coding: utf-8 -*-
# *****************************************************************************
#
# This program is free software; you can redistribute it and/or modify it under
# the terms of the GNU General Public License as published by the Free Software
# Foundation; either version 2 of the License, or (at your option) any later
# version.
#
# This program is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
# FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
# details.
#
# You should have received a copy of the GNU General Public License along with
# this program; if not, write to the Free Software Foundation, Inc.,
# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
#
# Module authors:
# Markus Zolliker <markus.zolliker@psi.ch>
#
# *****************************************************************************
"""driver for phytron motors"""
import time
from frappy.core import Done, Command, EnumType, FloatRange, IntRange, \
HasIO, Parameter, Property, Drivable, PersistentMixin, PersistentParam, \
StringIO, StringType, IDLE, BUSY, ERROR, Limit
from frappy.errors import CommunicationFailedError, HardwareError
from frappy.features import HasOffset
class PhytronIO(StringIO):
end_of_line = '\x03' # ETX
timeout = 0.5
identification = [('0IVR', 'MCC Minilog .*')]
def communicate(self, command):
ntry = 5
warn = None
for itry in range(ntry):
try:
_, _, reply = super().communicate('\x02' + command).partition('\x02')
if reply[0] == '\x06': # ACK
break
raise CommunicationFailedError(f'missing ACK {reply!r} (cmd: {command!r})')
except Exception as e:
if itry < ntry - 1:
warn = e
else:
raise
if warn:
self.log.warning('needed %d retries after %r', itry, warn)
return reply[1:]
class Motor(HasOffset, PersistentMixin, HasIO, Drivable):
axis = Property('motor axis X or Y', StringType(), default='X')
address = Property('address', IntRange(0, 15), default=0)
circumference = Property('cirumference for rotations or zero for linear', FloatRange(0), default=360)
encoder_mode = Parameter('how to treat the encoder', EnumType('encoder', NO=0, READ=1, CHECK=2),
default=1, readonly=False)
value = PersistentParam('angle', FloatRange(unit='deg'))
status = PersistentParam()
target = Parameter('target angle', FloatRange(unit='deg'), readonly=False)
speed = Parameter('', FloatRange(0, 20, unit='deg/s'), readonly=False)
accel = Parameter('', FloatRange(2, 250, unit='deg/s/s'), readonly=False)
encoder_tolerance = Parameter('', FloatRange(unit='deg'), readonly=False, default=0.01)
sign = PersistentParam('', IntRange(-1,1), readonly=False, default=1)
encoder = Parameter('encoder reading', FloatRange(unit='deg'))
backlash = Parameter("""backlash compensation\n
offset for always approaching from the same side""",
FloatRange(unit='deg'), readonly=False, default=0)
target_min = Limit()
target_max = Limit()
alive_time = PersistentParam('alive time for detecting restarts',
FloatRange(), default=0, export=False)
ioClass = PhytronIO
fast_poll = 0.1
_backlash_pending = False
_mismatch_count = 0
_step_size = None # degree / step
_reset_needed = False
def get(self, cmd):
return self.communicate(f'{self.address:x}{self.axis}{cmd}')
def set(self, cmd, value):
# make sure e format is not used, max 8 characters
strvalue = f'{value:.6g}'
if 'e' in strvalue:
if abs(value) <= 1: # very small number
strvalue = f'{value:.7f}'
elif abs(value) < 99999999: # big number
strvalue = f'{value:.0f}'
else:
raise ValueError(f'number ({value}) must not have more than 8 digits')
self.communicate(f'{self.address:x}{self.axis}{cmd}{strvalue}')
def set_get(self, cmd, value, query):
self.set(cmd, value)
return self.get(query)
def read_alive_time(self):
now = time.time()
axisbit = 1 << int(self.axis == 'Y')
active_axes = int(self.get('P37R')) # adr 37 is a custom address with no internal meaning
if not (axisbit & active_axes): # power cycle detected and this axis not yet active
self.set('P37S', axisbit | active_axes) # activate axis
if now < self.alive_time + 7 * 24 * 3600: # the device was running within last week
# inform the user about the loss of position by the need of doing reset_error
self._reset_needed = True
else: # do reset silently
self.reset_error()
self.alive_time = now
self.saveParameters()
return now
def read_value(self):
prev_enc = self.encoder
pos = float(self.get('P20R')) * self.sign
if self.encoder_mode != 'NO':
enc = self.read_encoder()
else:
enc = pos
status = self.communicate(f'{self.address:x}SE')
status = status[0:4] if self.axis == 'X' else status[4:8]
self.log.debug('run %s enc %s end %s', status[1], status[2], status[3])
status = self.get('=H')
if status == 'N': # not at target
if self.encoder_mode == 'CHECK':
e1, e2 = sorted((prev_enc, enc))
if e1 - self.encoder_tolerance <= pos <= e2 + self.encoder_tolerance:
self.status = BUSY, 'driving'
else:
self.log.error('encoder lag: %g not within %g..%g',
pos, e1, e2)
self.get('S') # stop
self.status = ERROR, 'encoder lag error'
self.value = pos
self.saveParameters()
self.setFastPoll(False)
else:
self.status = BUSY, 'driving'
else:
if self._backlash_pending:
# drive to real target
self.set('A', self.sign * self.target)
self._backlash_pending = False
return pos
if (self.encoder_mode == 'CHECK' and
abs(enc - pos) > self.encoder_tolerance):
if self._mismatch_count < 2:
self._mismatch_count += 1
else:
self.log.error('encoder mismatch: abs(%g - %g) < %g',
enc, pos, self.encoder_tolerance)
self.status = ERROR, 'encoder does not match pos'
else:
self._mismatch_count = 0
self.status = IDLE, ''
self.value = pos
self.read_encoder() # let encoder quickly match value
self.saveParameters()
self.setFastPoll(False)
return pos
def read_encoder(self):
if self.encoder_mode == 'NO':
return self.value
return float(self.get('P22R')) * self.sign
def write_sign(self, value):
self.sign = value
self.saveParameters()
return Done
def get_step_size(self):
self._step_size = float(self.get('P03R'))
def read_speed(self):
if self._step_size is None:
# avoid repeatedly reading step size, as this is polled and will not change
self.get_step_size()
return float(self.get('P14R')) * self._step_size
def write_speed(self, value):
self.get_step_size() # read step size anyway, it does not harm
return float(self.set_get('P14S', round(value / self._step_size), 'P14R')) * self._step_size
def read_accel(self):
if not self._step_size:
self.get_step_size()
return float(self.get('P15R')) * self._step_size
def write_accel(self, value):
self.get_step_size()
return float(self.set_get('P15S', round(value / self._step_size), 'P15R')) * self._step_size
def check_target(self, value):
self.checkLimits(value)
self.checkLimits(value + self.backlash)
def write_target(self, value):
self.read_alive_time()
if self._reset_needed:
self.status = ERROR, 'reset needed after power up (probably position lost)'
raise HardwareError(self.status[1])
if self.status[0] == ERROR:
raise HardwareError('need reset')
self.status = BUSY, 'changed target'
self.saveParameters()
if self.backlash:
# drive first to target + backlash
# we do not optimize when already driving from the right side
self._backlash_pending = True
self.set('A', self.sign * (value + self.backlash))
else:
self.set('A', self.sign * value)
self.setFastPoll(True, self.fast_poll)
return value
def stop(self):
self.get('S')
@Command
def reset_error(self):
"""Reset error, set position to encoder"""
self.read_value()
if self.status[0] == ERROR or self._reset_needed:
newenc = enc = self.encoder
pos = self.value
if abs(enc - pos) > self.encoder_tolerance or self.encoder_mode == 'NO':
if self.circumference:
# bring encoder value either within or as close as possible to the given range
if enc < self.target_min:
mid = self.target_min + 0.5 * min(self.target_max - self.target_min, self.circumference)
elif enc > self.target_max:
mid = self.target_max - 0.5 * min(self.target_max - self.target_min, self.circumference)
else:
mid = enc
newenc += round((mid - enc) / self.circumference) * self.circumference
if newenc != enc:
self.set('P22S', newenc * self.sign)
if newenc != pos:
self.set('P20S', newenc * self.sign) # set pos to encoder
self.read_value()
self._reset_needed = False
# TODO:
# '=E' electronics status
# '=I+' / '=I-': limit switches