frappy/frappy_psi/phytron.py
Markus Zolliker dfce0bdfbc phytron.py: improve status
better analysis of hardware status code

Change-Id: I667b443649db43ff3e572e0a50685aabc9ba2ca2
Reviewed-on: https://forge.frm2.tum.de/review/c/secop/frappy/+/32165
Tested-by: Jenkins Automated Tests <pedersen+jenkins@frm2.tum.de>
Reviewed-by: Markus Zolliker <markus.zolliker@psi.ch>
2023-09-19 10:57:59 +02:00

348 lines
14 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
limits switches are not yet implemented
"""
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
from frappy.states import HasStates, status_code, Retry
from frappy.lib import formatStatusBits
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, HasStates, 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 = PersistentParam("""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
_step_size = None # degree / step
_blocking_error = None # None or a string indicating the reason of an error needing clear_errors
_running = False # status indicates motor is running
_prev_diff = 0 # for checking progress
_intermediate_target = 0
_stopped_at = 0
status_bits = ['power stage error', 'undervoltage', 'overtemperature', 'active',
'lower switch active', 'upper switch active', 'step failure', 'encoder error']
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 clear_errors
self._blocking_error = 'lost position'
else: # do silently
self.clear_errors()
self.alive_time = now
self.saveParameters()
return now
def read_value(self):
return float(self.get('P20R')) * self.sign
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._blocking_error:
self.status = ERROR, 'clear_errors needed after ' + self._blocking_error
raise HardwareError(self.status[1])
self.saveParameters()
self.start_machine(self.starting, target=value)
return value
def hw_stop(self):
self._stopped_at = time.time()
self.get('S')
def doPoll(self):
super().doPoll()
if self._running and not self.isBusy():
if time.time() > self._stopped_at + 5:
self.log.warning('stop motor not started by us')
self.hw_stop()
def read_status(self):
for _ in range(3):
sysstatus = self.communicate(f'{self.address:x}SE')
try:
sysstatus = sysstatus[1:4] if self.axis == 'X' else sysstatus[5:8]
hexstatus = int(sysstatus, base=16)
status_items = formatStatusBits(hexstatus & 0xf7, self.status_bits)
if status_items:
status = ERROR, ', '.join(status_items)
else:
status = IDLE, ''
except TimeoutError: # Exception: # can not interprete the reply, probably communication error
self.log.warning('bad status reply %r', sysstatus)
continue
break
else:
status = (ERROR, f'unknown status after 3 tries {sysstatus!r}')
self._running = (hexstatus & 0x100) == 0
if status[0] == ERROR:
self._blocking_error = status[1]
return status
return super().read_status() # status from state machine
def check_moving(self):
"""checks while motor is moving
- in case motor is moving properly return Retry
- in case motor is moving in the wrong direction, return self.stopping_for_restart
- in case encoder does not follow steps, raise a blocking error
"""
prev_enc = self.encoder
if self.encoder_mode != 'NO':
enc = self.read_encoder()
else:
enc = self.value
if not self._running: # at target (self._running is updated in self.read_status())
return False
diff = abs(self.value - self._intermediate_target)
if diff > self._prev_diff and diff > self.encoder_tolerance:
# when the motor was started while running, without stopping first
# it happend that the motor run (almost) endless beyond the target!
# add this is to catch similar errors
self.hw_stop()
self.log.warning('motor is moving the wrong way')
return self.stopping_for_restart
self._prev_diff = diff
if self.encoder_mode != 'CHECK':
return Retry
tol = self.encoder_tolerance + abs(enc - prev_enc)
if abs(self.value - enc) <= tol:
return Retry
self.log.error('encoder lag: steps %g deviate by more than %g from encoder %g',
self.value, tol, enc)
self.hw_stop()
self.saveParameters()
self._blocking_error = 'encoder lag error'
raise HardwareError(self._blocking_error)
def start_motor(self, target):
if self.backlash and (target - self.value) * self.backlash > 0:
# drive first to target + backlash
target += self.backlash
self._prev_diff = abs(target - self.value)
self._intermediate_target = target
self.set('A', self.sign * target)
@status_code(BUSY)
def stopping_for_restart(self, sm):
self.read_status()
if self._running:
return Retry
self.start_motor(sm.target)
return self.driving
@status_code(BUSY)
def starting(self, sm):
self.read_status()
if self._running:
self.hw_stop()
return self.stopping_for_restart
self.start_motor(sm.target)
return self.driving
@status_code(BUSY)
def driving(self, sm):
self.read_status()
result = self.check_moving()
if result:
return result # Retry or self.stopping_for_restart
if self._intermediate_target != self.target:
self._intermediate_target = self.target
# drive to real target after intermediate target
self.start_motor(self.target)
return self.driving_to_final_position
return self.finishing
@status_code(BUSY)
def driving_to_final_position(self, sm):
result = self.check_moving()
if result:
return result # Retry or self.stopping_for_restart
return self.finishing
@status_code(BUSY)
def finishing(self, sm):
if sm.init:
sm.mismatch_count = 0
# finish
pos = self.read_value()
enc = self.read_encoder()
if (self.encoder_mode == 'CHECK' and
abs(enc - pos) > self.encoder_tolerance):
if sm.mismatch_count > 2:
self.log.error('encoder mismatch: abs(%g - %g) < %g',
enc, pos, self.encoder_tolerance)
self._blocking_error = 'encoder does not match pos'
raise HardwareError(self._blocking_error)
sm.mismatch_count += 1
return Retry
self.saveParameters()
return self.final_status(IDLE, '')
@status_code(BUSY)
def stopping(self, sm):
if self._running:
return Retry
return self.final_status(IDLE, 'stopped')
@Command
def stop(self):
self.hw_stop()
self.start_machine(self.stopping, status=(BUSY, 'stopping'))
@Command
def clear_errors(self):
"""Reset error, set position to encoder"""
self.read_value()
if self._blocking_error:
newenc = enc = self.read_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 and self.encoder_mode != 'NO':
self.log.info(f'enc {enc} -> {newenc}')
self.set('P22S', newenc * self.sign)
if newenc != pos:
self.log.info(f'pos {pos} -> {newenc}')
self.set('P20S', newenc * self.sign) # set pos to encoder
self.read_value()
self.status = 'IDLE', 'after error reset'
self._blocking_error = None
self.target = self.value # clear error in target