4. spec

spec is a x-ray diffraction software which is used at our beamline for the control of all devices, from the monochromator, slit systems up to the diffractometer. A general description of the capabilities of spec is give in the reference manual [Spe99]. See also the Internet page of Certified Scientific Software (CSS) http://www.certif.com/ for more information.

The aim of this chapter is to provide a simple manual for the use of the most important commands of spec and a description of the beamline specific features and macros. It is not intended to describe all commands implemented in spec. Advanced users should only read section 4.1 to learn about the non standart commands implemented exspecially for our beamline. Beginners should skip that section and start reading at section 4.2.

4.1 Site specific macros

atten value

Reads the actual setting of the filters and displays the thickness and the transmission for the actual energy if no argument is supplied. At the 6ID-B Main Station with argument it moves the absorbers according to the value (0 - 255), each bit represents one filter. At the 6ID-D Side Station the command atten bank value might have two arguments. If one argument is supplied (0 - 15) the specified number of filters is moved into the beam. At the 6ID-D Side Station there might be two filter banks installed. If two arguments are supplied the first argument is the filterbank which is to be used (1 or 2)

ugmv,umgvr

move up to 10 motors at the same time, see section 4.3

theta0

two theta correction, see section 4.9

read_ubm

reads a UB-matrice from rafin, see section 4.9

ana_elast

moves analyser theta and two theta, see section 4.7

absorption

calls a fortran program which calculates the transmission for different elements and energies

shutter command

opens or closes the main shutter, command are the words open or close. For the shutter of the idb- and idd-station the command idbshutter command and idbshutter command exists

new_fio_filename

and new_fio_copy implements the automatic creation of fio (Spectra) files during all scans. Package hp_fio.mac has to be loaded. new_fio_filename defines necessary variables and implements the creation of fio files. new_fio_copy defines a variable necessary for automatic copying of fio files to another computer. Package ssh has to be installed on both computers and the public key of the beamline computer has to be installed on the other computer. Look in the man pages of ssh. The macro show_fio_settings can be used to show the status of the fio package.

4.1.1 To move and scan PVs

The following commands are used to move or scan PVs, that are epics variables, e.g. the gap, that behave like motors.

pvwa

lists all PVs and their position

pvmv

moves a PV

pvascan

absolute scan of a PV

pvdscan

relative scan of a PV (also pvlup)

pvconfig

configure (add, delete, ...) PVs

4.2 Handling macros

qdofile(''filename'')

load macros defined in filename so that they are known to the program

prdef macroname

show code of macro macroname

lsdef

lists the names and sizes of macros

lscmd

lists build-in keywords and functions

newmac

reloads the startup macros, normally done when entering spec

4.3 Motors

umv motor pos

move motor to absolut position

umvr motor value

move motor relativ to actual position

wa

show positions of all motors (wu shows only mnemonic and user position)

wm mot1 mot2 mot3 ...

show positions of the specified motors

lm mot1 mot2 mot3 ...

show limits of the specified motors, without options the limits of all motors are shown.

ugmv mot1 pos1 mot2 pos2 ...

move group of motors to absolute positions

ugmvr mot1 val1 mot2 val2 ...

move group of motors relative to absolute positions

set motor position

sets the actual motor position to a new value

set_dial motor position

sets the actual dial motor position to a new value

set_lm motor low_limit high_limit

set new soft limits for a motor

zero motor

sets the dial value to the mechanical zero for motors which are equipped with a home position feature

tw mot1 mot2 ...delta1 delta2 ...sample_time

moves one ore more motors in small steps each time you hit the return key. The parameter sample_time is optional, if given after each move a count will be performed and displayed

4.4 General stuff

startup

Should be performed at the beginning of an experiment to set up data files and so on

newfile

changes to a new file where the data is written to

whats ???

gives information about an expression

gpset variable1 variable2

variable2 gets the same value than variable1 and the change is documented in the data file

sleep value

spec waits until the specified time in seconds has passed. If you use the command do_sleep instead spec will show a counter running backwards

setmono

set parameters for monochromator

4.5 Counting

ct time

counts for time seconds

uct time

counting is updated during count, try uctn if you have more than six counters

counters

changes the counter displayed during the scans

_show_cntr

shows current configuration of the counters

count

is the macro called by all scans and ct commands to do the counting

chk_beam

tests if beam is there, but normally the macro is not defined. Look into standard.mac to change this. If it is defined properly it waits until the beam is back if the intensity in the monitor (defined by global variable MON) is below the value defined in the global variable chk_thresh

Please note that a positive value of time represents counting for the defined time and a negative value represents counting against a monitor, which has to be defined by the counters command.

The global variables DET and MON contain the channel displayed during the scan and the monitor channel. They might be changed just by typing DET = ion1 then ion chamber 1 will be displayed during the scans.

4.6 Scans

Here a list of possible scans with a short explanation is shown. For details about the different scan types use spec command help.

ascan motor start_position end_position points sample_time

normal scan, positions are given in absolut values, scan contains one more point than given in points, last parameter is the sample time

a2scan motor1 start1 stop1 motor2 start2 stop2 points sample_time

two motor scan, also a3scan, a4scan and a5scan exist

dscan motor start_position end_position points sample_time

(or lup) relative scan, same like ascan but the values of start_position and end_position are added to the actual position. Also d2scan, d3scan, d4scan and d5scan exists

th2th tth_start_rel tth_finish_rel points sample_time

theta-two-theta scan

hklscan start_h stop_h start_k stop_k start_l stop_l points sample_time

Q-scan. In addition also hscan, kscan and lscan exists, easier to use if you are only doing scans in one Q-direction. Also more fancy Q-scans are available like hkcircle, hlcircle, klcircle, hkradial, hkradial and hkradial.

mesh motor1 start1 stop1 interval1 motor2 start2 stop2 interval2 sample_time

nested motor scan which is able to scan a two dimensional area defined by the two motors. Data is written to a single scan in the data file so make sure you are able to read the data with your data analysis software. The same exists for Q-scans, see hklmesh

aziscan azi_start azi_finish intervals sample_time

scan azimuthal angle

Escan start_E stop_E points sample_time

Energy scan

In addition also tscan, dtscan, abscan and abmesh scans exist but are not described here.

Please note that a positive value of sample_time in all scan types represents counting for the defined time and a negative value represents counting against a monitor, which has to be defined by the counters command.

After performing the scan the data of the counter displayed during the scan can be analyzed by the following commands (Note that to display a value a print command has to be added, e.g. p pl_MIN or the value has to be given to a variable, e.g. i = pl_MIN. Also a motor can be driven to the value umv tth CEN):

pl_MIN	smallest measured value (y)
pl_MAX	biggest measured value (y)
pl_xMIN	position (x) of minimum (y)
pl_xMAX	position (x) of maximum (y)
pl_SUM	sum of all measured values (y)
pl_SUMSQ	sum squared of all measured values (y2)
pl_FWHM	full width half maximum (y)
pl_CFWHM	center of FWHM (y)
pl_COM	center of mass (y)
pl_MINX	minimum (x)
pl_MAXX	maximum (x)
pl_LHMX	upper half-maximum of (x)
pl_UHMX	lower half-maximum of (x)

For convenience CEN is identical to pl_CFWHM.

4.7 Energy

Here commands related to the monochromator are given. Warning! Energies in spec are given in keV and not in eV! Make shure to type moveE 7.930, do not forget the dot if you want to go to the gadolinium L_II-edge. Do not mix it up with the HASYLAB standart. The 6ID-D Side Station is using a special custom designed monochromator. In addition to the commands mentioned in this section the commands special for the sidestation are described in section 4.11.6.

getE

displays the actual energy

moveE energy

move monochromator to energy.

setE energy

this command recalibrates the monochromator motors. Never use it unless you are really knowing what you are doing

ana_elast value

drives the theta and two theta of the analyser (tha, ttha) to the correct positions for the actual energy. For this purpose to the variable ANALYSER_d_spacing has to be assigned the correct value. If this is done the analyser will also be moved automatically whenever the energy of the monochromator is changed (also in an Escan (section 4.6)). To omit this assign a value $\leq$ 0 to ANALYSER_d_spacing. If an energy is submitted as an arguement to ana_elast the analyser will not be moved but the positions will be calculated and shown. This is for testing purpose

setanalyser

calculates lattices constants for different analysers. This is a command only available at the 6ID-D Side Station. Should be self explanatory.

spec is internally working with the wavelength lambda, which is accessible through the global variable LAMBDA. With the command calcE which is automatically invoked by moveE, getE and setE a new value for LAMBDA can be calculated. The Energy in keV can easily be calculated with the global variable hc_over_e performing hc_over_e/LAMBDA as is done by getE.

4.8 Temperature control macros

There are some predefined temperature control macros:

te value

reads temperature or sets setpoint if value is supplied

teramp

ramps a temperature

These macros are only working if the macros settemp and measuretemp are defined. For an example to define these macros see the spec manual or call your system administrator.

4.9 UB-matrix

List of usefull commands related to the UB-matrix:

4.9.1 Commands from

ca h k l

calculate positions for h k l

ubr h k l

move to position h k l

wh

display h, k, l, tth, th, chi, phi, etc.

pa

display geometry parameter

showUB

Displays the actual used UB-matrix. Please note that it differs by a factor of 2$\pi$ from the results of the program rafin, also the matrix was transponated.

enterUB

enables you to enter a UB-matrix directly.

setlat

sets the lattice parameters of the sample. Is is also possible to set directly the reciprocal lattice parameters with setrlat

or0

set actual position to be first orientation reflection

or1

set actual position to be second orientation reflection

setor0

and setor1 same like the commands or0 and or1 but not the actual position is used, you have to enter the position of the reflections manually

or_swap

exchange first and second orientation relection set with the commands or0 and or1

savegeo

prints all information necessary for UB-matrix or monochromator setup on the screen. The user is responsible for printing this or writing it into the logbook!

save

executes savegeo and saveusr and saves it to hard disk. saveusr is normally empty and could for example contain user defined global variables

cuts

displays the angles which th, chi and phi will not cross but instead reach the position from the other direction. cuts name value will change one of them, cuts value value value value will change all four

setmode

sets the mode the UB-matrix is working in. Value is stored in variable g_mode. For explanation execute command setmode or look into the spec manual [Spe99]

freeze value

Freezes depending on the mode (see setmode) one or more angles to the actual value or if parameter value is supplied to the supplied value. This is exspecially usefull if you always want to go to your reflections is one or more angles fixed regardless where the actual position of this angles is. The command is rewoked with the command unfreeze. The command pr_freeze displays the actual frozen values

setsector value

choses a symmetry transformation out of 8 possible transformations, value 0 means no transformation. See the spec manual for an detailed explanation [Spe99]

sectors H K L

displays all motor positions for all possible sectors

setaz

set azimutal reference

startgeo

asks for all necessary information, executing the commands setmode, setsector, setlat and setaz

cz H0 K0 L0 H1 K1 L1

calculate zone: prints the values of chi and phi needed to put two vectors in the scattering plan

mz H0 K0 L0 H1 K1 L1

move zone: calculates the necessary chi and phi, moves there and then goes into the fixed zone mode (g_mode = 2)

sz H0 K0 L0 H1 K1 L1

set zone: calculates the necessary chi and phi and then goes into the fixed zone mode (g_mode = 2), freezing chi and phi on these values

calcG

calculates the UB-matrix. This routine is normally called by all commands which change the configuration of the UB-matrix, for example or0 and or1

reflex H K L

stores the actual position as reflex named H K L in a file. Before the first reflection can be stored command reflex_beg has to be executed. After all reflections are stored execute reflex_end. Follow the instructions on the screen if you want obtain a new UB-matrix from a fit of these reflections

calcL

after a custom made UB-matrix was entered or fitted with the reflex commands, calcL calculates the lattice parameters for the real and reciprokal lattice from the UB-matrix

The following commands are custom made commands, defined in the file hp_ubm.mac, see 4.11.11.

richt

small programm that calculates reflex positions fast and efficient and is in principle self-explanatory, at least if you understand german

theta0

this command reads the information about the two reflections from which the UB-matrice was derived and calculates a correction for two theta and the lattice constant. It works only for cubic systems or if both reflections used pointing in directions with the same lattice constant

ubm_read filename

reads a UB-matrix from filename. If filename is not given it will be read from ubfrom.raf. Afterwards UB-matrix will be transposed and multiplicated with a factor 2$\pi$ to make it workable with spec.

For a definition of the UB-matrix see [Bus67].

Small trick if you only plan to do measurements in one direction: Measure two reflections, for example (0 0 2) and (0 0 4) and do a correction with the program theta0. Afterwards with the commands or0 and or1 use the same reflection (e.g. (0 0 4)) for the UB-matrix, but name it (0 0 4) for or0 and (0 4 0) for or1. Of course you get an error message. Now set one of the variables g_u12 or g_u13, they represent chi and phi of the second reflection, to a value which differs by 90 degree from the original one. You now have created a virtual (0 4 0) reflection. To calculate a new UB-matrix finally execute the command calcG. You now have a UB-matrix which should work perfect in the (0 0 4) direction but contains no information about other directions.

4.10 Tips for programmers

Usefull macros that should be loaded at each spec session wether or not you are starting fresh can be saved in the file spec.mac in the current directory where spec is executed or in the file site.mac in the specd directory, usually /usr/local/lib/spec.d. In addition site macros which only should be loaded while starting with option fresh should be saved in site_f.mac.

Very important for programmers is also the possibility to execute loops, this is done by the command for. A short example for doing a mesh-scan manually follows:
for (i=20; i<=21; i+=0.1) {
umv th i
lup tth -1 1 20 1
}
Also a while command using the C-syntax exists.

Very important: When defining macros put the complete macro in a {} surrounding if you want to avoid that local defined variables become global known.

_check0 motor

checks if a motor name is valid

move_em

is a macro that starts all motor movements with the build in function move_all. Before the movement starts the macro user_premove is executed and afterwards user_postmove. Both are normally emty.

show_cnts

reads the scalers and shows the contents but did not count by itself

4.11 Explanation of the different custom made macros

In this section a collection of macros, sorted by the filenames in which they are defined is explained. They are not of general interest for every user but might be usefull for specific tasks. At the 6ID-D Side Station most of these macros are preloaded by the macro site_f.mac which is residing in the home directory of spec macros (normally in /usr/local/spec/lib/) at the beamline computer and executed at every fresh start.

4.11.1 hp_fio.mac

This package contains macros which are usefull for people who are familiar with the HASYLAB, DESY program spectra and are using it for their data analysis. The package redefines user entry points supported by the standart.mac package delivered with spec to write fio-files. In addition the following commands have been defined to do the setup of the package:

fio_show_settings

shows if the writing of fio files is in use

fio_new_filename

this command is used to start creation of fio files or to change the name of the created fio files

fio_new_copy

if fio files are created and the beamline computer is able to use ssh (not the case for ID-B) and has an authorized key on another system this command can be used to set up an automatic copying of the fio files to the second computer. Might be usefull as backup or for data analysis

See also section 3.2.3 for an explanation of these commands.

4.11.2 GPIB macros

Normally GPIB and serial input and output is directly supported by spec. Because of the problem with the generic EPICS serial and GPIB support it is necessary to have special macros available which allow users a conveniant and consistant way to address external devices. The macros in this section provide the users with the following two commands:

hp_gpib_get address

reads a value from a serial or GPIB device. Address is the GPIB address of the device if it is a positive integer, the absolut value of address is the serial address of the device if address is a negative integer. Because spec does not support user functions (at least not very easy), the return value will be found in the variable GPIB_val

hp_gpib_put address value

writes value to the serial or GPIB device address (see above)

Because of spec problems with the proper handling of value which can be a string or a variable it is strongly recommended to use the command in the following way: dummy = ``test1234'';hp_gpib_put address dummy Usage of for example hp_gpib_put 24 ``SETP? 1'' which is a typical command for the lakeshore model 340 will lead to strange error messages. dummy = ``SETP? 1'';hp_gpib_put 24 dummy is the workaround, so only use variables as argument for hp_gpib_put.

If only the hp_gpib_get and hp_gpib_put commands are used macros can be easily interchanged between beamlines. For example hp_SI_controller.mac (section 4.11.3) and hp_lakeshore340.mac (section 4.11.4) only use these two commands to communicate with the devices independent if they are connected to the serial port or the GPIB. A beamline specific macro package than connects these two commands to the actual used serial port or GPIB. Two examples are given, section 4.11.2 for sector 11, BESSRC-CAT and section 4.11.2 for sector 6, $\mu$-CAT

4.11.2.1 hp_gpib_11id.mac

At BESSRC-CAT a gpib card is used which is supported by spec. Thus hp_gpib_11id.mac is very short and the commands hp_gpib_get and hp_gpib_put are only projected to the spec commands. Only a terminating character is added if necessary.

4.11.2.2 hp_gpib.mac

At the $\mu$-CAT 6ID-B Main Station and 6ID-D Side Station EPICS generic serial and GPIB records are used to communicate with for example temperature controllers. This complicates the communication with devices and made the development of hp_gpib.mac necessary. These macro package supports both the generic serial record and the generic GPIB record. It allows the usage of several GPIB devices at the same time even though only one generic GPIB record is available and handels all necessary changes which have to be made to the generic GPIB record automatically. It has to be configured properly which is normally done by the system administrator. For configuration read the source code in the file hp_gpib.mac.

4.11.3 hp_SI_controller.mac

This is a package for the use of a Scientific Instruments temperature controller. It requires that hp_gpib.mac is loaded first. It is not recommended to use the Scientific Instrument temperature controller in experiments, it is outdated hardware, for example the temperature setpoint can only be changed in 0.1 K steps. This package redefines the macros measuretemp and _settemp so that the temperature commands supplied by standart.mac (see section 4.8) are working.

4.11.4 hp_lakeshore340.mac

The hp_lakeshore340.mac package is for the use with a lakeshore model 340 temperature controller. It works together with package hp_gpib.mac (see 4.11.2), this package has to be loaded first. It has three main funtions: Change the setpoint and measure the temperatures during the scan. The measurements are done during the scalers are busy with counting, look into the source code for details. Second, write and read sensor calibration curves to and from the lakeshore and third, allow the configuration of importand parameters and allow to save or read them from hard disk.

lakeshore340_help

Displays a short help of all commands and also shows the values of global variables used to configure the lakeshore macros.

lakeshore340_config_settemp

configures the global variables for the settemp macro

lakeshore340_read_curve curve_number filename

Reads a curve and displays it. If optional filename is given it will be written to harddisk

lakeshore340_write_curve

reads a curve from disk and send it to the lakeshore

lakeshore340_settings option

execute program without parameter option, it will show all possible values of mode. Allows to change, save, restore of lakeshore parameters

lakeshore340_set_pid

changes PID parameters and heater range

lakeshore340_set_mode

changes temperature control mode

lakeshore340_set_control

configures control sensor

lakeshore340_set_zone

configures one zone of PID parameters

lakeshore340_set_ramp

configures ramp parameter

lakeshore340_set_settle

configures settle parameters (lakeshore signals with status bit if temperature is stable)

For the lakeshore340_set_pid and the lakeshore340_set_ramp command parameters can be set up on the command line, just enter the command followed by the appropriate number of parameters (4 and 2).

This short description does not replace the manual of the lakeshore 340 model. Read the manual und use the hp_gpib_put and hp_gpib_get commands to write your own macros.

4.11.5 hp_move.mac

The hp_move.mac package provides the commands gmv, gmvr, ugmv, ugmvr, which are able to drive one to ten motors at the same time. This package might be used to replace the old move commands of standart.mac. For a description of these commands see 4.3.

4.11.6 hp_mono_6idd.mac

The macro hp_mono_6idd.mac provides special commands for operating the 6ID-D Side Station monochromator. These special commands are needed for two reasons: First the 6ID-D Side Station monochromator consists of three monochromator crystal pairs and these macros enable the user to easily exchange them. Second the second monochromator moves over a large distance. If the energy is changed by several MeV a realignemend is necessary.

setmono value

This macro replaces the setmono macro distributed with spec. The original macro can be found under _setmono. With the setmono command a monochromator crystal pair can be choosen and spec automatically makes all changes necessary to change the monochromator crystals. If value is the number of a valid monochromator crystal pair the change will be done immidiately, otherwise an interactive menue will be displayed

mono_accept_position energy

The 6ID-D Side Station monochromator covers a very large energy interval. The monochromator is working very stable but if big changes in the energy are made the alignement of the monochromator changes a little bit. Once the monochromator has been aligned for a certain energy mono_accept_position can be used to calibrate the monochromator to the correct energy. Warning! Do not use the standart spec command setE for this purpose, it will work for the moment, but the energy calibration of the monochromator will be lost in the long term.

mono_calc_position energy

calculates the theoretical positions for the motors monu, mond and montrav for a given energy.

mono_calc_energy_range

calculates the energy range which is covered by the actually used monochromator.

mono_show_settings n

shows all parameters for the monochromator with number n, if no number is supplied it shows the parameters for the actually used monochromator.

mono_show_all

shows all parameters for all available monochromators.

mono_align_crystals

This macro aligns the beam on the second monochromator crystal. To do so the second monochromator is moved to several different positions and at each position a scan with the $\vartheta$ of the first monochromator crystal is done. The range where these scans are done depends on the energy and the chosen monochromator crystal pair. This macro does not do any data analysis. The user is responsible to analyse the data and to chose a suitable position for the monochromator pairs.

mono_save_values filename

all relevant information about all three monochromators is stored in a file named filename on the harddisk. To reset all variables to these values execute this file with the command qdofile, for an explanation see section 4.2. These information is also stored on harddisk, whenever for example the command mono_accept_position is executed. The files are stored in the subdirectory monochromator in the SPECD directory. This is normally the directory where for example the standart macros of spec are placed. To see where this is just type p SPECD.

_mono_determine_crystal

This macro determines which crystal is actually in use by looking at the position of motor m1_xtal, the crystal changer of the first monochromator and than assigns the number of the crystal to the global variable mon_num.

4.11.7 hp_motor_6idd.mac

The commands defined in the file hp_motor_6idd.mac are used to control the special Huber diffractometer if the 6ID-D Side Station. The 2$\vartheta$ rotation for the vertical scattering mode of this diffractometer consists of two translations and one rotation. All motors of the 6ID-D Side Station are described in section 2.2. In this macro the movement of the virtual motors described in table 2.1 is implemented. All motor movements are normally done automatically, the following commands are intended for the setup of the diffractometer.

diffractometer_mode_change value

Changes the mode in which the virtual motors operate. Mode 0 means no coupling between virtual and real motors, all movements of virtual motors will not affect any real motor. Mode 1 means the diffractometer is in vertical mode and mode 2 means the diffractometer is in horizontal mode. If virtual motors are used in this mode the corresponding real motors will move. See section 2.2 for a detailed description which motors are coupled. If no value is given the command will show the options and ask for a value.

ana_elast

see section 4.7

setanalyser

see section 4.7

To be able to simulate the vertical 2$\vartheta$ rotation three variables have to be set. This is done in the first lines of the file hp_motor_6idd.mac, for the actual values see table 4.1. The variable dist_sample_analyser defines the distance between the sample mounted in the center of rotation of the diffractometer and the analyser. During the simulated 2$\vartheta$ rotation this distance will stay constant. The variables zero_tt_y and zero_tt_z define the position of the motors tt_y and tt_z for 2$\vartheta$ = 0. For tt_y this is the difference between the zero of the encoders and the beam hight, when the beam is going through the center of rotation of the diffractometer. Because in the moment the encoder for motor tt_z is not working the zero position is determined by using a plumb to put the analyser directly above the sample position. Therefore, zero_tt_z and dist_sample_analyser have the same value.

Table 4.1: Actual values for the variables used for the setup of the virtual 2$\vartheta$ movement in vertical scattering geometry

Variable name	value
dist_sample_analyser	924.31
zero_tt_y	5.26
zero_tt_z	924.31

4.11.8 hp_mca.mac

The Canberra Detector system used at the 6ID-D Side Station is operated through a Canberra computer interface called AIM 556. This AIM controls a digital signal processor (DSP) with integrated support of a multi channel analyser (MCA) and a high voltage (HV) power supply for the detector. There are several MEDM screens available to control the HV power supply and the DSP. In addition a graphical display of the MCA is provided. The setup of the HV power supply and the DSP should be done by experienced staff members. Normally not two many changes should be necessary. Two remarks to operation:

• The DSP can be used in coincidence or anticoincidence mode. It is only counting if the regular counters are running or not running at the same time, respectively.
• it is possible to connect an analog single channel analyser (SCA) to the test output of the DSP, this way the DSP is used as an ordinary amplifier. This makes life a lot easier, because the regular counters can be used.

Warning! hp_mca.mac requires that hp_fio.mac was loaded before hp_mca.mac.

The MCA features are available in spec, they are provided by the macro package hp_mca.mac. This package does not use any specific commands of the DSP and therefore should work together with any MCA system supported by EPICS. This package only provides basic features. In the moment the data is only stored in the fio format of Spectra. During counting done with this macro package the display of the MEDM window is not updated. The reason is that updated consume to much time so that not all photons will be collected if the MCA is read out.

mca_count filename time

The mca counts for the given time and the result is saved into a file with name filename. Both arguments are optional. If only one argument is given that must be time. If no or only one argument is given the filename is constructed from the variables MCA_NAME and MCA_NUMBER.

mca_new_filename

Use this command to define a filename and a starting number. Whenever the mca_count command is used without the optional filename the name defined in here is used. If MCA files are written during scans they will have the name of the fio file with an additional number corresponding to the point in the scan where the MCA spectrum was taken. If no FIO_NAME is defined the MCA_NAME will be used and the user is responsible to keep track which file belongs to which point and scan.

mca_mode_change number

The MCA macro knows three modes:

0

- MCA not in use

1

- MCA in use but only regions of interest (ROI) are read out

2

- MCA in use, at each scan point a MCA spectrum is written to disk

Argument number is optional, if omitted possible arguments are shown and the user is asked for his choice.

mca_energy_calibration

With this command the user gets an easy interface to do an energy calibration. In principle nothing more is done then defining four variables, MCA_cal_ch1, MCA_cal_ch2, MCA_cal_ener1 and MCA_cal_ener2. Two channel numbers and the corresponding to energies are needed. For the 6ID-D Side Station a Co_57 source is a good choice, it has two lines at 122 keV and 136.5 keV.

MCA data files will be automatically copied to the same place like the fio files, see section 4.11.1 for explanation how to copy files.

4.11.9 hp_DAC_vmic4116.mac

The macros in this file control the VMIC 4116 digital analog converter (DAC). This device is a 16 bit DAC which is able to provide voltages in the range from -10 V to +10 V.

dac_volt channel value

Applies a voltage to one of the eight channels. Channel has to be a value between 0 and 7, value is the voltage between -10 and +10

dac_bit channel value

Applies a voltage to one of the eight channels. Channel has to be between 0 and 7, value is a bit value between 0 (corresponds to -10 V and 65535 (corresponds to +10 V)

dac_init

This command initialises the DAC. This command is automatically called by dac_volt or dac_bit if necessary. It should only be necessary if the VME crate was switched off. Nevertheless this command can be called at any time without doing any harm.

4.11.10 hp_filter_6idd.mac

hp_filter.mac controls the filter. It also calculates the absorption. All values are automatically stored in each scan. It is also possible to calibrate the filters at certain energies and have those calibrated values written into the data files. See section 4.1 for commands for explanation of the atten command which controls the filters. In addition there are some more commands in this file which might be usefull:

marshutter word

Opens or closes a small shutter built by Peter Hiller which might be very helpfull together with the image plate system. Word has to be replaced by open or close.

absorption

Calculates absorption values

filter_calibration

This command does an automatic calibration of the filter bank which is actually in use by changing the intensity with detuning the monochromator and moving the filters out of the beam one by one at the same time. This command might not work correctly and is very primitive. It should be replaced as soon as possible with a programm which uses both filterbanks instead of detuning the monochromator.

filter_show_calibration bank

Shows if the filter bank with number bank has been calibrated and if this is the case shows the calibration

filter_save_calibration filename

Saves the actual calibration of both filter banks in a file named filename. This file can later be executed with the qdofile command to regain the stored values

4.11.11 hp_ubm.mac

hp_ubm.mac contains macros which allow you to do some calculations related to the ub-matrix and other usefull stuff. See section 4.9 for details, all commands of this macro are listed in the section with the custom made commands. Originally this macro package was intended to work together with the rafin program which refines UB matrices from a given list of reflections and provide other usefull things related to UB matrices. Unfortunately it was never finished. The only things which are usable right now is the theta0 command based on an old fortran program from Thomas Brückel which helps to set up a UB matrix from two reflections for cubic systems and the hp_read_ubm command which is able to read output from rafin into spec. richt is a small programm to calculate the positions of reflections written by Oliver Hermann Seeck (unfortunately in German).

4.11.12 hp_mar.mac

The macro hp_mar.mac is a preliminary macro to control the Mar Image Plate Scanner with spec written on November 27th, 2001 during a beamtime at the 6ID-D Side Station. It is not fully tested but it was working during that beamtime and it is only providing very limited support of the features the Mar Image Plate Scanner offers. Feel free to improve it.

Known bugs: Sometimes a command is given by spec and never reaches the Mar Image Plate Scanner. Commands are transfered by the program package ssh which is one ore two times a day not working reliable. Also keep in mind that this package is only working if there is a working and compatible version including public and private key infrastructure on the beamline and image plate control computers. Due to changes in the operating systems of the computers the used ssh and scp commands might have to be modified.

There is one important global variable: MAR_ON. If MAR_ON is greater then 0 The small shutter build by Peter Hiller will be opend and closed for each counting command.

mar_show_settings

Shows the configuration of the Mar Image Plate scanner control variables.

mar_setup

Configures the Mar Image scanner control variables.

mar_execute

Sends a command to the Mar Image Plate Scanner.

mar_wait_for_imageplate

Waits until a command is finished on the Mar Image Plate Scanner.

mar_read

Reads and erases the Mar Image Plate Scanner and waits until it is finished and ready for the next exposure.

4.11.13 dw_shutter.mac

dw_shutter.mac written by Didier Wermeille contains the commands shutter word, idbshutter word, idcshutter word and iddshutter word. They are used to open the shutters. word has to be replaced by open or close to open or close the shutter, respectively.

4.11.14 dw_pv.mac

This macro package written by Jonathan Lang and Didier Wermeille provides commands to move and scan epics variables, the commands are described in section 4.1.1. On the 6ID-D Side Station a version is running which automatically executes the command pvdefine if necessary. On the 6ID-B Main Station if one of the PV macros asks you to execute the command pvconfig and you do not want to make changes to the configuration file it is sufficient to execute the command pvdefine.

4.11.15 dw_escan.mac

In this macro written by Didier Wermeille the Escan command provided within the spec package is redefined. During every energy scan the actual Q-position at each energy will be written to the data file. The macros in hp_fio.mac will automatically notice this change and the Q-positions are also written into the fio files.