hardware_interfaces.triax module¶

Name:

triax - various functions for TRIAX spectrometer control

Description:

This module provides the class Triax to control TRIAX spectrometers over RS232 to the extent that was used in the original mess.frm Visual Basic Script.

This is therefore NOT (yet) a complete implementation of the entire interface as given in the doc, since the other command were apparently not needed.

Warning

When the spectrometer looses power unexpectedly during operation, normal init may fail. It seems that the communications buffer must be cleared first, and the new init procedure does just that. It has not yet been tested though.

Classes:

Triax

main()¶: For testing purposes: establish communication and read current state

Versions:

200322 - initial commit, Georg Wille

References

Spectrometer_control_interfacing_programming_manual.pdf

class Triax(hwconfig=None, port: str = 'COM1', turret: str = 'default', gamma: float = - 9.984, d: float = 30.0, f: float = 190.0, w: float = 2.0, step_slit: float = 2.0, pixel_pitch=0.25, pixel_number=64, pixel_center=32, tgratings: Optional[list] = None, init=False, baudrate: int = 19200, bytesize=8, parity='N', stopbits=1, timeout=1.0, xonxoff=True)[source]¶

Bases: object

Represents a Triax spectrometer connected via serial port.

By default, object instantiation only tries to set up communication and, if successful, read out the current state. Hardware initialization has to be requested by parameter or performed separately afterwards.

The following attributes have a method for setting them via a set_xxx method, all others are derived from there:

grating
slit
wavelength
wavenumber

Parameters

hwconfig (hwconfig object) – object provided by hardware properties module, containing all hardware information. IF SPECIFIED, THIS SUPERSEDES ALL EXPLICITLY GIVEN SPECTROMETER AND MCT PARAMETERS.
port (str, optional) – serial port name. Defaults to ‘COM1’
turret (str, optional) – turret name. Defaults to “default”. Purely decorative.
gamma (float, optional) – angle (degrees) between normal of center wavelength beam and focal plane. Defaults to -9.984
d (float, optional) – angle (degrees) between entrance and exit arm, fixed for given spectrometer geometry. Defaults to 30.0
f (float, optional) – focal length (mm). Defaults to 190.0
w (float, optional) – entrance slit width (mm) solely for calculating the wavelength axis. Defaults to 2
step_slit (float, optional) – factor for conversion of slit motor position to true slit width. slit width = step_slit * slit position. Defaults to 2.0
pixel_pitch (float, optional) – center-to-center distance of MCT pixels (mm). Defaults to 0.25
pixel_number (int, optional) – number of pixels per line. Defaults to 64.
pixel_center (int, optional) – index of pixel that gets the central wavelength. Defaults to 32.
tgratings (list, optional) – lines/mm for gratings in positions 0,1,2 of current turret. Defaults to [300., 150., 100.]
init (bool, optional) – immediate hardware init. Defaults to False
baudrate (int, optional) – baud rate. Defaults to 19200
bytesize (optional) – data bits. Defaults to serial.EIGHTBITS
parity (optional) – parity bit. Defaults to serial.PARITY_NONE
stopbits (optional) – number of stop bits. Defaults to serial.STOPBITS_ONE
timeout (float, optional) – timeout in seconds. Defaults to 1.0
xonxoff (bool, optional) – enable software flow control. Defaults to True

ser¶: serial port connection object

is_connected¶

spectrometer is properly communicating

Type: bool

grating¶

current grating (one of 0, 1, 2)

Type: int

gr_line_density¶

current grating line density in lines/mm

Type: float

slit¶

current slit width in µm

Type: float

slit_pos¶

current slit position in motor steps

Type: int

wavelength¶

current true central wavelength in nm

Type: float

wavelength_base¶

current central wavelength in nm w.r.t to base grating of 1200 l/mm

Type: float

wavenumber¶

current central wavenumber in cm-1

Type: float

wn_axis¶

list of wavenumbers in cm-1 on each detector pixels, length of list depending on pixel number from hardware setting

Type: ndarray

wl_axis¶

list of wavelengths in nm on each detector pixels, length of list depending on pixel number from hardware setting

Type: ndarray

turret¶

current turret

Type: str

tgratings¶

lines/mm for gratings in positions 0,1,2 of current turret.

Type: list

step_slit¶

factor for conversion of slit motor position to true slit width. slit width = step_slit * slit position

Type: float

gamma¶

angle (degrees) between normal of center wavelength beam and focal plane

Type: float

d¶

angle (degrees) between entrance and exit arm, fixed for given spectrometer geometry

Type: float

f¶

focal length (mm)

Type: float

w¶

entrance slit width (mm) for wavelength axis calculation

Type: float

pixel_pitch¶

center-to-center distance of MCT pixels (mm)

Type: float

pixel_number¶

number of pixels per line

Type: int

pixel_center¶

index of pixel that gets the central wavelength

Type: int

MAX_WAVELENGTH = 20000.0¶

MIN_WAVELENGTH = 2500.0¶

__init__(hwconfig=None, port: str = 'COM1', turret: str = 'default', gamma: float = - 9.984, d: float = 30.0, f: float = 190.0, w: float = 2.0, step_slit: float = 2.0, pixel_pitch=0.25, pixel_number=64, pixel_center=32, tgratings: Optional[list] = None, init=False, baudrate: int = 19200, bytesize=8, parity='N', stopbits=1, timeout=1.0, xonxoff=True)[source]¶: Initializes new spectrometer object instance and establish communication.

cli(init=False)[source]¶

Implements a tiny command line interface for TRIAX access

Parameters: init (Boolean, optional) – call init procedure first? Defaults to False.

end()[source]¶: Puts Triax spectrometer in defined state and ends communication.

exit_click()[source]¶: If no collection is running: closes COM port and moves motors 1 and 2 to position 0.

form_unload()[source]¶: Always closes COM port and moves motors 1, 2 to position 0.

init_spectrometer()[source]¶: Initializes spectrometer.

new_init_spectrometer()[source]¶: Initializes spectrometer according to manual.

set_grating(new_grating: int)[source]¶

Changes to the given grating position.

Sets the current turret to one of its three positions. Instance attributes grating and gr_line_density will be changed accordingly. If an error occurs, these will be set to None.

Parameters: new_grating (int) – 0, 1 or 2

set_slit(new_slit: float)[source]¶

Changes slit width.

Sets the slit to the new width. Instance attributes slit and slit_pos will be changed accordingly. If an error occurs, these will be set to None.

Parameters: new_slit (float) – new slit width in micrometers

set_wavelength(new_wavelength)[source]¶

Changes central wavelength.

Sets the central wavelength to the new value. Instance attributes wavelength, wavelength_base, wavenumber, wn_axis and wl_axis will be set accordingly. If an error occurs, these will be set to None.