class spex750m(object):
"""
A class implementing standard Jobin-Yvon serial commands
for simple spectrometers like the SPEX 750M.
By default, this class is configured to look for the 750M
plugged into ``/dev/ttyUSB0`` (the first port on the USB-serial
adapter, when run under linux).
"""
def __init__(self, addr=None):
"""
Connect to the spectrometer and initialize its hardware.
:param addr: the serial interface where the
spectrometer is found.
Default: ``/dev/ttyUSB0``
"""
if addr is None:
addr = self._default_location
self.bus = Serial(addr, timeout=10, baudrate=19200)
try:
self.init_hardware() # try to initialize hardware.
except InstrumentError as err:
print("%s, rebooting once..." % err)
self.reboot() # in case of trouble, reboot
self.init_hardware() # and try again.
# 750M specific data
_steps_per_nm = 4000
_default_location = '/dev/ttyUSB0'
def __str__(self):
return 'Spex 750M'
def boot_status_check(self):
"""Check the boot status of the controller.
- \* : Just Autobauded
- B : Boot Acknowledged
- F : Just Flashed
"""
self.bus.readall()
resp = self.bus.ask(' ') # send autobaud character
if len(resp) == 0:
raise InstrumentError("750M did not give a boot status")
elif resp[0] in ("*", "F", "B"):
return resp[0]
else:
raise InstrumentError("Unknown 750M boot status: %s" % resp)
def reboot(self):
"""Reboot the controller if it's not responding"""
return self.bus.ask("\xDE")
def _hi_iq(self):
"""Send the HI IQ character to the controller.
(Duplicates functionality of F7-247.vi.)
Returns True if it's ok to flash the controller
afterward.
"""
self.bus.readall()
resp = self.bus.ask("\xF7")
if resp[0] == "=":
return True
else:
raise InstrumentError("750M HI IQ command failed")
def _flash(self):
"""Flash the controller by sending the O2000<null>
string to it.
"""
return self.bus.ask("O2000\x00")
def init_hardware(self):
"""Initialize 750M hardware. I don't know why this
works, I just copied Yan's LabView routine.
"""
status = self.boot_status_check()
if status == "*":
self._hi_iq() # * -> B
self._flash() # B -> F
status = self.boot_status_check()
if status == "F":
return True
else:
raise InstrumentError("750M hardware init failed.")
def wait_for_ok(self, expected_bytes=1):
"""
Wait indefinitely for the 'o' status byte.
This function waits until a certain number of bytes
(usually just one) are present on the bus. When
that data arrives, the first bye is read
and checked to make sure it's the "okay" status.
"""
while self.bus.inWaiting() < expected_bytes:
# as long as the buffer is empty, hang out
sleep(0.050)
# read the status byte when it arrives
resp = self.bus.read()
if resp != 'o':
raise InstrumentError("750M operation failed: %s" % resp)
def calibrate(self, wl_value):
"""Read the current wavelength from the window
and pass it to this method (units of nm) to recalibrate
the 750M.
"""
self.bus.readall()
cmd = "G0,%d\r" % (wl_value * self._steps_per_nm)
self.bus.write(cmd)
self.wait_for_ok()
_busyCodes = {"q": True, "z": False}
def is_busy(self):
"""Check if the motors are busy. """
self.bus.write("E")
self.wait_for_ok()
resp = self.bus.readall()
return self._busyCodes[resp]
def rel_move(self, distance_to_move):
"""Move the grating by the given
number of nanometers."""
self.bus.readall()
cmd = "F0,%d\r" % (distance_to_move * self._steps_per_nm)
self.bus.write(cmd)
self.wait_for_ok()
while self.is_busy():
# wait for the motors to rest
sleep(0.050)
def get_wavelength(self):
"""Query the current wavelength """
self.bus.readall()
self.bus.write("HO\r")
self.wait_for_ok()
resp = self.bus.readall(term_chars='\r')
# convert to wavelength units
wl = int(resp) / float(self._steps_per_nm)
return wl
def set_wavelength(self, wl):
"""Move to the wavelength value specified.
contingent on proper calibration, of course.
"""
if wl < 0 or wl > 1500:
raise InstrumentError("Out of Range")
distance_to_move = wl - self.get_wavelength()
self.rel_move(distance_to_move)
wavelength = property(get_wavelength, set_wavelength)
# abbreviate 'wavelength' to 'wl'
get_wl = get_wavelength
set_wl = set_wavelength
wl = wavelength
class spex750m(object):
"""
A class implementing standard Jobin-Yvon serial commands
for simple spectrometers like the SPEX 750M.
By default, this class is configured to look for the 750M
plugged into ``/dev/ttyUSB0`` (the first port on the USB-serial
adapter, when run under linux).
"""
def __init__(self, addr=None):
"""
Connect to the spectrometer and initialize its hardware.
:param addr: the serial interface where the
spectrometer is found.
Default: ``/dev/ttyUSB0``
"""
if addr is None:
addr = self._default_location
self.bus = Serial(addr, timeout=10, baudrate=19200)
try:
self.init_hardware() # try to initialize hardware.
except InstrumentError as err:
print "%s, rebooting once..." % err
self.reboot() # in case of trouble, reboot
self.init_hardware() # and try again.
# 750M specific data
_steps_per_nm = 4000
_default_location = "/dev/ttyUSB0"
def __str__(self):
return "Spex 750M"
def boot_status_check(self):
"""Check the boot status of the controller.
- \* : Just Autobauded
- B : Boot Acknowledged
- F : Just Flashed
"""
self.bus.readall()
resp = self.bus.ask(" ") # send autobaud character
if len(resp) == 0:
raise InstrumentError("750M did not give a boot status")
elif resp[0] in ("*", "F", "B"):
return resp[0]
else:
raise InstrumentError("Unknown 750M boot status: %s" % resp)
def reboot(self):
"""Reboot the controller if it's not responding"""
return self.bus.ask("\xDE")
def _hi_iq(self):
"""Send the HI IQ character to the controller.
(Duplicates functionality of F7-247.vi.)
Returns True if it's ok to flash the controller
afterward.
"""
self.bus.readall()
resp = self.bus.ask("\xF7")
if resp[0] == "=":
return True
else:
raise InstrumentError("750M HI IQ command failed")
def _flash(self):
"""Flash the controller by sending the O2000<null>
string to it.
"""
return self.bus.ask("O2000\x00")
def init_hardware(self):
"""Initialize 750M hardware. I don't know why this
works, I just copied Yan's LabView routine.
"""
status = self.boot_status_check()
if status == "*":
self._hi_iq() # * -> B
self._flash() # B -> F
status = self.boot_status_check()
if status == "F":
return True
else:
raise InstrumentError("750M hardware init failed.")
def wait_for_ok(self, expected_bytes=1):
"""
Wait indefinitely for the 'o' status byte.
This function waits until a certain number of bytes
(usually just one) are present on the bus. When
that data arrives, the first bye is read
and checked to make sure it's the "okay" status.
"""
while self.bus.inWaiting() < expected_bytes:
# as long as the buffer is empty, hang out
sleep(0.050)
# read the status byte when it arrives
resp = self.bus.read()
if resp != "o":
raise InstrumentError("750M operation failed: %s" % resp)
def calibrate(self, wl_value):
"""Read the current wavelength from the window
and pass it to this method (units of nm) to recalibrate
the 750M.
"""
self.bus.readall()
cmd = "G0,%d\r" % (wl_value * self._steps_per_nm)
self.bus.write(cmd)
self.wait_for_ok()
_busyCodes = {"q": True, "z": False}
def is_busy(self):
"""Check if the motors are busy. """
self.bus.write("E")
self.wait_for_ok()
resp = self.bus.readall()
return self._busyCodes[resp]
def rel_move(self, distance_to_move):
"""Move the grating by the given
number of nanometers."""
self.bus.readall()
cmd = "F0,%d\r" % (distance_to_move * self._steps_per_nm)
self.bus.write(cmd)
self.wait_for_ok()
while self.is_busy():
# wait for the motors to rest
sleep(0.050)
def get_wavelength(self):
"""Query the current wavelength """
self.bus.readall()
self.bus.write("HO\r")
self.wait_for_ok()
resp = self.bus.readall(term_chars="\r")
# convert to wavelength units
wl = int(resp) / float(self._steps_per_nm)
return wl
def set_wavelength(self, wl):
"""Move to the wavelength value specified.
contingent on proper calibration, of course.
"""
if wl < 0 or wl > 1500:
raise InstrumentError("Out of Range")
distance_to_move = wl - self.get_wavelength()
self.rel_move(distance_to_move)
wavelength = property(get_wavelength, set_wavelength)
# abbreviate 'wavelength' to 'wl'
get_wl = get_wavelength
set_wl = set_wavelength
wl = wavelength
