12. Command cheatsheet

This section provides a quick summary of the data acquisition commands discussed in the previous sections.

Stopping a measurement

To stop any command do Ctrl-C Ctrl-C

That is, hit Ctrl-C twice!

This will pause the running command and return you to the command line.

Do RE.resume() to continue the command from where it stopped.

Do RE.stop() to fully stop the command.

12.1. The most essential information

Note

Parentheses – () – are an essential part of the syntax. Same for RE() and % when specified.

12.1.1. Most common commands

shb.open() / shb.close()

Open / close the photon shutter

RE(mv(dcm.energy, <value>))

Move TO an energy value

RE(mv(xafs_y, <value>))

Move any named motor TO a position (xafs_y is an example)

RE(mvr(xafs_y, <value>))

Move any named motor BY an amount (xafs_y is an example)

RE(change_edge('Xx'))

setup beamline for an absorption edge, Xx = 1- or 2-letter symbol, e.g. Cu or Y.

RE(slot(<N>))

Move sample wheel to slot #N (1 ≤ N ≤ 24)

RE(xafs_wheel.outer()) / RE(xafs_wheel.inner())

move the ex situ wheel sample holder to the outer/inner ring

%xrf

measure and display an XRF spectrum

RE(linescan(<motor>, <detector>, <start>, <stop>, <N>))

move a motor, plot a signal

RE(pluck())

Select a point from a plot on screen and move that motor to that position

xlsx()

import a spreadsheet

RE(xanes())

quick-n-dirty XANES scan at the current element and edge

12.1.2. Most common motors

See Section 4.1 for the full list of xafs_ motors.

motor	type	units	notes	directions
xafs_x	linear	mm	main sample stage	+ outboard, - inboard
xafs_y	linear	mm	main sample stage	+ up, - down
xafs_det	linear	mm	detector mount	+ away from sample, - closer

12.2. Full list of commands

Note that some command must be run through the run engine, other do not. The use of RE() is called explicitly in Table 12.1. Any command that should be run through the run engine will complain with this hint:

BMM D.111 [48] > mvr(xafs_x, 2)
Out[48] <generator object mvr 0x7fefafd1df50>   Hint: enclose bsui commands in RE()

Table 12.1 Main BlueSky commands used at BMM (don’t type the < or >, those symbols indicate that the argument is numeric.)

Shutter commands
shb.open() / shb.close()	Open / close the photon shutter
Mono tuning commands
RE(rocking_curve())	Measure the 2nd crystal rocking curve
tu() / td()	Tune the mono 2nd crystal by hand
TUNE_STEP=0.004	Tuning step size – 0.004 is good for Si(111), 0.002 for Si(311)
Import an automation spreadsheet
xlsx()	Select an existing spreadsheet from a list
Mono movement commands
RE(mv(dcm.energy, <value>))	Move TO an energy value
RE(mv(dcm.energy, <e0value> + 50))	Move 50 eV above the edge
RE(mv(dcm.energy, <e0value> - 50))	Move 50 eV below the edge
RE(mvr(dcm.energy, <value>))	Move BY an energy step
Motor movement commands
RE(mv(xafs_y, <value>))	Move any named motor TO a position (xafs_y is an example)
RE(mvr(xafs_y, <value>))	Move any named motor BY an amount (xafs_y is an example)
Where are things?
%w dcm	where’s the mono?
%w slits3	where are the slits?
%w m2	where’s mirror 2? (toroidal focusing mirror)
%w m3	where’s mirror 3? (flat, harmonic rejection mirror)
%w xafs_table	where’s the XAFS table?
Change edge and mono crystal
RE(change_edge('Xx'))	setup beamline for an absorption edge, 1- or 2-letter symbol
RE(change_xtals('h11'))	set monochromator, Si(111) or Si(311), h=1 or h=3
Experiment setup
RE(slit_height())	explore position of slits3 (then pluck to move dm3_bct)
RE(dark_current())	measure electrometer dark currents
ex situ sample stage
RE(slot(<N>))	Move sample wheel to slot #N (1 ≤ N ≤ 24)
RE(find_slot())	align the ex situ wheel sample holder
RE(xafs_wheel.outer())	move the ex situ wheel sample holder to the outer ring
RE(xafs_wheel.inner())	move the ex situ wheel sample holder to the inner ring
Glancing angle stage
RE(ga.to(N))	move glancing angle stage to sample N (1 ≤ N ≤ 8) + start spinner
RE(ga.auto_align(pitch))	automatically align glancing angle stage and move to pitch
Linkam stage
RE(mv(linkam, T))	move Linkam stage to temperature T
linkam.settle_time = 120	set Linkam settling time (in seconds)
linkam.status()	display Linkam status
linkam.on() / linkam.off()	turn Linkam on or off
LakeShore temperature controller
RE(lakeshore.to(T, power))	move cryostat to temperature T with heater at power
lakeshore.settle_time = 120	set Linkam settling time (in seconds)
lakeshore.status()	display Linkam status
RE(mv(lakeshore.power,3))	turn heater to full power
RE(mv(lakeshore.power,0))	turn heater off
Reference wheel
RE(reference('Xx'))	Move to reference ‘Xx’
Get help
%m	Show motors
%h	Show help
%k	Show keyboard shortcuts
%se	Show reference foil and ROI configurations

12.3. Photon delivery system modes

Table 12.2 Photon delivery system modes

Mode	focused	energy range
A	✓	8 keV and up
B	✓	below 6 keV
C	✓	6 keV to 8 keV
D	✗	8 keV and up
E	✗	6 keV to 8 keV
F	✗	below 6 keV
XRD	✓	8 keV and up

12.4. Slits3 coordinated motions

These coordinated motions behave just like single motors and can be used with the motor movement commands in Table 12.1.

Horizontal size

slits3.hsize (nominally 8 mm)

Horizontal center

slits3.hcenter (nominally 0 mm)

Vertical size

slits3.vsize (nominally 1 mm)

Vertical center

slits3.vcenter (nominally 0 mm)

The vertical center should never be changed. Instead, align the slits using dm3_bct and the slit_height() plan (Section 6.2)

Example movement: RE(mv(slits3.vsize, 0.5))

Individual slits are named slits3.top, slits3.bottom, slits3.inboard, slits3.outboard.

12.5. Motor positions and limits

These commands work on any named motor (Table 4.1).

Where is a sample motor?

%w xafs_x

What are the soft limits?

xafs_x.hlm.value / xafs_x.llm.value

Set a soft limit:

xafs_x.hlm.put(-95) / xafs_x.llm.put(-157)

12.6. Line scans

RE(linescan(<motor>, <detector>, <start>, <stop>, <N>))

where

• <motor> is a named motor, see Table 4.1

• <detector> is one of: 'it', 'if', 'ir', or 'i0'

• <start>, <stop>, <N> are the boundaries relative to the current position and the number of steps.

The plot will be determined from the values of <motor> and <detector>

This is a relative scan.

After the scan, you will prompted to select a position to move to. Single click the left button after a linescan to move to a position.

RE(pluck())

to repeat that on the current plot.

12.7. Energy scans

Start an XAFS scan, prompting for an INI file (section 7.1)

RE(xafs())

Start an XAFS scan using a specified INI file (section 7.1)

RE(xafs('myscan.ini'))

In the INI file, set mode to transmission, fluorescence, reference, or both to control the in-scan plotting display (both = show transmission and fluorescence)

Import a spreadsheet to perform automated XAFS measurements:

xlsx()

You will be prompted first for the name of a spreadsheet file, then for the tab to be read.