CAD4

Because there is no Technical User Manual on the Internet site and the CAD4 is out of production for some time, the Service Manual has been made available for the customers, but first read the conditions.
• Safety see MACH3 instructions
• Error searching lists
• General
• Versions
• Technical  data
• Operation
• Software commands
• Pocket terminal
• Measuring crystals
• Maintenance and service
• Programmable IC's
• Led's
• Specifications

Conditions

• The Service Manual is written for service man with experience, so can sometimes be too compressed for customers. It is also less cared for then a Technical User Manual.
• The use of this manual is for responsibility of the customer. If you are not sure: ask Service and we will point out which part can be used.
• Bruker AXS cannot give free technical assistance for problems, caused by using this manual or other use which is not connected to a specific error.

• Start-up and communication errors
• Positioning errors
• Pocket terminal error messages
• Program errors, Crystal measuring errors
• Error messages
• Intensities skipped: copied previous data
• Crystal axes too long or too short
• Problems with Search
• Program stops after HV-off
• Crash (Collision)
• Shutter does not open
• HT falls off when using the shutter
• Attenuator does not work
• Intensity problems
• Computer problems

• Check the fuse at the back of the interface.
• Be sure no residual CAD4 programs are running in the background as a result of a non standard previous exit.
• Be sure to use the best start-up:
• First start the program till it waits with the output : ".... Connection is made to CAD4 process ....."
• Power-up the interface
• Check the 5V power during starting up, when a high current is running.
• Be sure there is no collision during start-up. Check it by putting an isolator (piece of paper) between the collision switches.
• Errors during porgram startup:
• If the programs ends with: unit 3 = ......
• Check if the GCU unit (if present) power is on
• "Return Code 0": this means that the program is aborting itself (normally with Ctrl-Y): probably an unreliable PC.
• Check the RS232 indicator on front of the Interface (or with older CAD4 : mount a RS232 indicator between the CC connector and RS232 cable) and check
• After start-up the TXD should flash once.  If not :
• After TXD the RXD should flash. If not then there is a problem with the computer
• Check the Computer  program
• Try another RS232 port of the computer
• TXD and RXD flash and the computer program runs till "CAD4H" (PC-DOS or Digital)
• C
• Check the Bus interface 0546.604/614/554
• Check with a digital probe the RS232 signal trough IC32 and return trough IC33 (HCPL 2531) or replace both at once.
• Check in the pocket terminal if the text "CAD4H" is running. When it stands still or is absent, the program is dead.
• The problem can now be in any part of the electronic, such as the processor. Send the interface to the factory for repair.

• No motors are running :
• Check the motor power supply in the Substitution unit (LED's on the outside).
• General
• Change in GONCON,   CASPAR:   PA = 10 (checks on a larger positioning error). When the goniometer runs all right this setting can be used temporary till the next maintenance service visit.
• On the pocket terminal press: arrow, 7, move, axis  and when it runs press: 0. Now the axis should stop. If it runs the motor board is defect.
• Interchange both motor boards and check if the problem is now in the other axis. If it is then the error is in a board.
• Oscillation (noise in the motor) :
• If on a fixed position: probably an encoder problem.
• Check the motor constants with GONCON, CASPAR, O with the factory values on the paper in the accessories box.
• Omega:
• One of both motors defect: Remove the motor wires and turn them by hand. It should run very smooth.
• Check bearings: are they worn or rusty?
• Check the gears: is there dirt or much backlash?
• It could even be the column, but that is difficult to check
• Axis running full speed in one direction
• Remove the Motor Generator board
• if still running at full speed the error is in a Motor drive board in FR58.. or Substitution unit.
• if not running then probably the opto isolator on the Motor Generator board is defect.
• All axes 3 degree wrong position:
• Check the Encoder ADC zero/max. If this is not successful: new encoder board.
• Phi and Kappa :
• Check if there is a defect in the cable running trough the centre of the goniometer:
• Rotate Omega and check in the pocket terminal if Phi or Kappa position change. If it does, the wires to the encoder are broken
• Run Phi or Kappa (arrow 6) and rotate Omega by hand (by opening the plate on the readout dials). Check if the motor runs smoothly. If not then the wires to the motor are broken
• If case of an error: change the cable.
• Theta (sticks) :
• Remove the side plate of the Omega indicator. Rotate the indicator by hand. When it is not running smoothly, probably the column is defect, perhaps caused by overflowing with nitrogen.
• Remove the side plate of the Theta indicator. Rotate the indicator by hand. When it is not running smoothly, probably the course encoder is defect. When it sticks every 2.8º it is the fine encoder. If it sticks on one position : the coarse encoder. The mechanics must be dismantled to check where is the error.
• Does it stops once at low speed? Sometimes the dial counter has a heavy switch-over point. When it does not repeat it is no problem.
• Remove the dial at the side of the goniometer, which can run heavy. It is not essential for measurements.
• Stops often: with Turbo-CAD4: motor worn. Open the motor at the back and check if the collimators are worn.
• Omega
• Does it stops once at low speed? Sometimes the dial counter has a heavy switch-over point. When it does not repeat it is no problem.
• Remove the dial at the side of the goniometer, which can run heavy. It is not essential for measurements.
• Stops often: with Turbo-CAD4: motor worn. Open the motor at the back and check if the collimators are worn.
• Other: run on the pockterminal the TEST ALL.
 

211                        13212 5413                       44042 24071                     626655 52362222220000000000000000305075

Coarse: Coarse encoder not at zero. Can cause the axis at 2.8º wronmg position. Erro is very rare, mostly when some one has changed something on the encoder. Solve by: rezero
• Slits positioning problem:
• Never change the dial position relative to the encoder, because realign can only be done in the factory.
• Positioning always has a tolerance of several bits, because it has backlash to let the mechanical click determine the exact position.
• Remove the cap of the dial unit and inspect the mechanical click.
• Check if the ball of the spring is still present
• Position the slit both from right and from left and check if the dial always falls in the slit position.
• Never change the position of the spring, unless you are sure the position does not change. Realign the dial unit can only be done in the factory.
• Check if the motor has an active stop :
• On pocket terminal press : arrow, 6, move, dial. The dial will now rotate.
• Press : 0. The dial should now stop immediately
• Check on broken wires :
• On pocket terminal press : spec, dial. This will show the dial position.
• Rotate Theta and check if the dial position does not change.
• Set the slit positive and negative with Theta on maximum positions and check if the dial positions are all right.

• Running out of crash:
• Electronic
• Stop all operations (when working with the pocket terminal : CLEAR).
• Check which axis must be moved to recover from crash position and in which direction.
• In pocket terminal press : > 3 MOVE axis CRASH. (> or < depending on direction : > = positive, < = negative). The goniometer will now move a small step. Check if it moves in the right direction. Repeatedly pressing CRASH moves the goniometer out of the crash switch, then it will move continuously.
• Stop movement with CLEAR.
• Mechanical
• Remove the side plate of the Omega or Theta dial and move it by hand out of crash.
• Crash message without real crash.
• Now and then crasH
• Check if the crash switches (at both collimators) is not to sensitive. This can be done by slightly pushing or slide piec of paper in teh switch (only temporary!) and check if the crashes disappear.
• It can be caused by electronic spikes on the crash line. Place a capacitor of 1 uF on the Motor Generator board between IC11 pin 1 ("LIMSW") and TP18 (GND).
• Check the voltage between the metal parts of the collision switch (see circuit)
• If +12V then the opto IC11 on the Motor generator board is defect
• If 0V then remove the Motor generator board and measure again:
• If +12V then opto IC11 is defect
• If 0V then there is still a real short circuit in the crash circuit.

• Check with command WO if the right X-ray tube is selected.

• The red shutter lamp goes on (temporary) but the shutter does not open. This error is mostly caused by a safety error. Check in which part is the error:
• Shift the collimator backwards as far as possible with the right pin position.
• Override the enclosure safety by connecting the flashing lamp to the Enclosure connector (goniometer connector 1). Be sure the lamp is flashing. If the shutter now opens, check if all the doors are closed.
• Place new lamps in the red shutter on lamp.
• When you have recently (re)mounted the monochromator or X-ray port : Loosen the two screw of the monochromator/X-ray port, press it to the collimator holder and fasten the screws again.
• Below the collimator holder there are two connections with a red and blue wire (the collimator safety). Short circuit them and check if the shutter opens. If so: inform Service. For safety : never use this short circuit permanent.

The shutter does not close fast enough so the safety electronics detects an open shutter while it should be closed. It is indicated by a red computer led on the FR586 or shutter message on the FR590. A service men must readjust the shutter or probably replace the shutter coil. It is possible to remain working temporary by opening the shutter with the pocket terminal before the measurement, so it will be open continuously. Because the shutter is always open this is only allowed when all safeties are active, like the enclosure safety. The beam open lamp must not flash.

Attenuator does not work

• Set the attenuator and rotate the Theta axis. When the attenuator comes in now and then, the wire in the Theta cable is broken. The cable must be replaced by a servicemen.

• No intensity:
• Check all fuses at the Interface backside
• Measure the HV at the coax cable at the detector side it should be about the same as the pocket terminal HV value.
• If not present:
• Check if the HV connector is mounted in the right connector at the interface
• Probably the Power board defect.
• Set the generator to 25 kV, 5 mA. Attenuator on, aperture to 9 mm, Theta = 0, pin hole in collimator place, remove beam stop and measure the primary beam. Give the result to the Service.
• Intensity too low:
• Be sure there is no obstruction anywhere in the X-ray path: attenuator up, no slit in place (open hole).
• Measure the intensity with Effic
• Readjust the HV
• Mount a new X-ray tube
• Realign the X-ray optics

• With rotating anode:
• Check in GONCON • CASPAR if it is set as rotating anode.
• There is a difference in program:
• Unix (Argus) and DOS : If HV does not return within 1.5 minute, the program is stopped, asking if it should proceed.
• EXPRESS is always starting trough.

• Check if you using the right search parameters
• Check if you are using the right setpar parameters
• Try another setting : SETPAR 2 / / / / / /

When for some reason a reflection could not be measured, the data of previous reflection is put into the log file.

• Check the code if it shows a reason of not measuring

• "collision": predicted collision
• "crash-switch detected": real collision
•  "fading #me/#ref <<err": The data collection is interrupted because an intensity-control reflection has become too weak. #me = as measured, #ref = expected, err = max difference
• Check the generator setting
• Check the alignment of the crystal
• "hard interrupt": defect Encoder board (micro-processor)
• "noise": Intensity too low, reflection reset to "no valid information"
• "not found": The reflection is not found and its line is deleted form the Crystal file
• "positoning time-out error": The data collection is interrupted because the goniometer could not be positioned properlyu within 10 minutes. See above
• "strong": intensity was above 50 kcps
• "switch xxx1": The program was intterrupted by the user with a switch xxx1 set. To continue it is necessary to reset this switch
• "user interrupt": Program stopped by Ctrl-C or Ctrl-S from the host computer.
• "weak": Intensity too low, reflection reset to "no valid information"

• Digital (VAX)
• Does not boot, ends with >>>> prompt
• Type command: SHOW BOOT.
• The computer will search for a boot disk. If he finds one then command: BOOT device name
• If he does not find one then the disk is defect. Unless you can find an old second hand part or repair shop the computer is not useful anymore.
• New Linux or Express program does not run : Check upgrade
• After command Zero or View, the message: HARD INTERRUPT
• Collision switch activated
• Respond with : /

• Shutter circuit
• HV-on circuit
• Motor/encoder mechanical
• Crash/Collision circuit
• Potmeter (servo) test
• Motor encoder board
• Goniometer constants
• Register (status read)
• Output files
• Connections, fuses, boards
• Software: What software is available now (status September 2009, Frank van Meurs): see the CAD4/MACH3 user page on the Nonius site.

HV-on circuit overview

Motor/encoder mechanical overview

Crash/collision circuit

Potmeter test, TEST ALL

This test checks the servo system, mostly the behaviour of the encoder potmeters.

• Connect a printer or terminal to the RS232 CT port. at the backside of the Interface. see specifications
• Start the test on the pocket terminal with: • , move, 5 (or other option).
• Output :

Theta	Phi	Fine test.  Measures during running the difference between wanted and real position of the fine potmeter in digitization bits
Omega	Kappa
Theta	Phi	Coarse test  Measures during running the difference between the 5 overlap bits of the fine and course potmeter (positioning errors will exist with overflows, so with errors larger then 15 columns).
Omega	Kappa
- Limits : width <14 columns and not two peaks. Mostly the fine test will show an error. - The left bit is all overflows (+ and -) - Other errors

Examples

Motor encoder board

To change opto couplers (type HP 2531). When changing it is advised it mount them on a IC socket

 

Register

• Read out the status register with the pocket terminal: 174124 MOVE 0 (Motor generator board IC29)
• Normal output with X-ray on and shutter closed: CA 177760
• CA 177761 = X-ray off (bit D0 = 1)
• CA 177762 = Shutter switch indicates an open shutter (bit D1 = 1)
• CA 177770 = Collision detected (bit D3 = 1)

• Program and general
• Crystal file
• Measure and position
• Standard output of measurement
• Error messages
• EXPRESS

Crystal file
 

GONCON, FCRYST, Y, name, Y, Q, LK, 1, 25	Makes a new crystal file with max. 25 reflections (then do SEARCH). See User manual page 9/2
LO #1 #2	Shows the list of reflections from reflection #1 to #2. Output :  n - h - k - l - * - Theta - Phi - **s - attenuator/speed - width (3*FWHM in º) - counts
LH, h k l	Adds a reflection to the list (then do SETANG to measure)
LK, #1 #2	Removes reflections #1 to #2 from the list.
LCA, #, A, Y	Sets a reflection "unmeasured" (then do SETANG to measure).
RO	Displays : data and orientation of the crystal.
WO	Displays : X-ray tube, Lam1 and Lam2 (wavelength of alpha1 and alpha2, depending on X-ray tube) and attenuator filter factor.
WI	For input the : X-ray tube (Mo, Cu, Ag, Cr, Co, Fe) and attenuator filter factor.

Measure, position
 

SETANG	Measures the "unmeasured" reflections in the list. Output :  n - * - Theta/K - S - Phi/K - Omega/K - Kappa/K - Phi/E - Omega/E - Chie/E - Shifts.....
SCAN, axes, SA, N, R	Scan axes ( = P, T, O, K). SA = angle (º), N = speed (º/min = N/16.48), R = ratio of two axes (1-6).
SCAN, N, time	Intensity / time measurement without moving axes (multiple measurements). Switch = 0001 : only one measurement.
SEARCH, T K P, SP DV	Search new reflections for the empty places in the crystal file. See SEARCH T C P = Phi scan on position Theta and Chie.  SP = Scan speed 1 - 12 (x16.48 º/min).  DF = Discrimination factor peak/background.
SETPAR, swoma swomb diafra diafrb scanr qfact pfract	Scan parameters. See Measure crystal swoma, swomb = the omega scan is swoma + swomb * tan(Theta)  diafra, diafrb = the aperture is diafra + diafrb * tan(Theta)  scanr = scan ratio  qfact = Quality factor  pfract = Poisson distribution factor  Output : SETPAR with input / / / / / /.
LG, n, .P KP, Theta Phi Omega Kappa EP, Theta Phi Omega Chie MK ME	Position goniometer axes    Output : position	on reflex n  in Kappa  in Eulerian  in Kappa  in Eulerian
SAP, n	Position of the aperture. Default : 9 mm / open hole. n = mm
SP  SN  SH  SV	Position to slit	positive skew  negative skew  horizontal  vertical
SA  RA	Attenuator	in  out
SO SC	Shutter	Open  Close

Standard output of a measurement (paper User Manual chapter XI-E, page 29)

Type 0

type

list nr 1-25

H

K

L

code

Theta º

Phi-K º

Omega-K º

Kappa º

NPI = Scan speed  16.48/NPI º/min  - = with attenuator

Scan width

Netto intensity

default example:

1

-3

-1

12

N*****

3

Type 1

	type	reflection number	H	K	L	code	Psi	Npi = Scan speed  16.48/Npi º/min  - = with attenuator	Background intensity left  sum profile 1-16	Intensity  sum profile 17-80 type 3	background intensity right  som profile 81-96	?	?
number of characters:	2	6	5	5	5	7	7	4	6	7	6
default example:	1	1450	-3	-1	12	N*****	.00	3	14	2424	8	793.3	16.7

Type 2

	type	reflection number	Theta º	Phi-K º	Omega-K º	Kappa º	Width Omega scan  º	Cumulative X-ray time s	Fridl
number of characters:	2	6	8	9	9	9	7	7	3
default example:	2	1450

Typ 3-10

	type	reflection number	96 dumps of intensities of the scan columns with intensity vertical in cnt
default example:	2	1450	3211133            06340015           725067656 00000000005307517334222220000000000

Code reflection status (see paper User Manual, chapter XI-E, page 30)

• N***** = normal
• I***** = intensity control
• N**W** = weak reflection
• N**S** = strong reflection
• N**T** = too strong reflection, even with attenuator
• NC**** = predicted collision
• ND**** = Shift oif the reflection more then DANG
• NX**** = Chie > 100º, so no positioning possible

It is also possible to work with the basic (old) CAD4 program:

• Build a stand-alone CAD4:
• Command: @expressgen cad4
• Do everything asked for after the above command
• Copy: [express.system]accesscode.exp to: [cad4.system]
• SET DEF [CAD4.SYSTEM]
• @CAD4 0

• Normal (customer) use
• Service use
• Error messages

Pocket terminal, service use
 

SPEC, axis  SPEC, MOVE, axis	Encoder position (potmeter) of the chosen axis. Output in octal value  - Choice : C/F = coarse/fine, D/S = Cosine/Sine  - Default after clear : course and cosine	Coarse and fine. Choose C/F  Potmeter. Choose C/F and D/S
•, MOVE, 5 –, MOVE, 5 SPEC, axis, degree, MOVE, 5	Potmeter (servo) test, course and fine.	Course and fine  Only course  Over degree of axis from present position
address, MOVE, 0	Data read
HV, LL, WD	Detector HV voltage, Lower Level and Window.  xxx MOVE HV. Change HV. this will not be saved in GONCON !  > n MOVE HV/LL/WD Scans HV, LL or WD with speed n.
xxx MOVE PAUSE	Set CAD4 CT port (not the host !) to xxxx baud . This is not saved in GONCON!

Program error messages
 

•  see paper User Manual chapter VI-G, page 19
• "hard interrupt": defect Encoder board (micro-processor)

For testing, use the test crystal.

Measuring a crystal

Scan parameters setting with SETPAR.

• Default :
• With Mo :
• Default : SETPAR, 0.80 0.35 2.40 1.05 6. 1.00 1.00
• Sharp or strong reflection : SETPAR, 0.45 0.35 1.90 1.05 6. 0.60 2.50
• With Cu :
• Default : SETPAR, 0.80 0.15 2.40 0.43 6. 1.00 1.00
• Sharp or strong reflection : SETPAR, 1.20 0.15 3.00 0.43 6. 2.00 0.70

• Look in the crystal list with LO.
• If it is empty :
• Command SEARCH, [T] 0 90, 12 2
• If it is not empty (also when it is from another crystal) :
• Remove reflections 1-3 (LK, 1 3) and : SEARCH, [T] 0 90, 12 2
• Remove reflections 4-6 (LK, 4 6) and : SEARCH, [T] 15 90, 12 2
• Remove reflections 7-9 (LK, 7 9) and : SEARCH, [T] 30 90, 12 2
• Remove reflections 10-12 (LK, 10 12) and : SEARCH, [T] 45 90, 12 2
• This will search reflections at different positions, which will index more quickly.
• [T] = 7 for Mo and 15 for Cu
• When it cannot find a reflection, try another setting

Connections, fuses, boards

Boards

Goniometer

• 1 : 4 pin, Radiation safety shield (safety switches) or safety override flashing lamp.
• 2 : 6 pin, Optional Kappa Limit safety switch. When not used, a dummy connector must be mounted.
• 3 : 2 pin, Crystal illumination (24V, max. 80 mA)
• 4 : 7 pin, to the Pocket terminal (adapter).
• 5 : "G" cable to the FR586 or Substitution unit.
• 6 : "M" cable to the Goniometer Interface.

Goniometer Interface

• M : "M" cable, to the goniometer
• R : "R" cable, to the 586 or Substitution unit
• CT : RS232 connection for an extra console terminal or printer.
• CC : RS232 connection to the Host computer.
• When using a PC with 9 pin connector: buy a standard RS232 0-modem cable or connect as:

25 pin	9 pin
pin 2	pin 2
pin 3	pin 3
pin 7	pin 5
pin 4 to pin 5 and pin 8	pin 1 to pin 7 and pin 8
pin 6 to pin 20	pin 4 to pin 6

• HT : High Voltage to the detector
• Rad. det. : Signal to the detector
• Signal out : Not used (amplified analog count signal)
• Mains : Power input and primary power fuses (220 V: 1 A, 110 V : 2 A, slow blow)
• F1 : Fuse 1A slow blow. For isolated +5V (Detector input, encoder input, RS232 in/output)
• F2 : Fuse 0.5 A slow blow. For detector HV.
• F3 : Fuse 0.5 A slow blow. For isolated +/-15V (Detector input, encoder input, RS232 output)
• F4 : Fuse 0.5 A slow blow. The same as F3.
• 1 : For optional analog rate meter.

This chapter contains only small parts or changes of the paper manual.

• Yearly maintenance is strongly advised for a long life time of accurate working. This can only be done by a service technician.
• Tools
• X-ray optics alignment with a sealed tube
• Detector HV adjustment
• Encoders
• ADC zero/max
• Adjust
• Effic to check the X-ray/alignment efficiency: the same as MACH3. The values are the same. It needs a standard absorber, mounted on the collimator: for Mo part number 0540.331, for Cu part number 0540.330.
• Open the goniometer
• Lubricate:
• for omega and theta worm axis Teflon oil is used. It has no part number. Ask Delft.
• for the gearing wheels cad4 mach3 and kappaccd triflon greas

Part number SAP 4020016
• No parts number for the oil we have a little
• Upgrade to Express or Linux software
• +5V adjustment
• Replacement
• Omega cable change
• Encoder units
• Shutter dismount/remount
• Phi encoder/motor unit (dis)mount

Tools

• Test crystal Ammonium bitartate. Order number 0516351T. Large crystal, oriented. a = 7.648, b=7.844, c=11.068 Angstrom

X-ray optics alignment with a sealed tube

The alignment is the same as with the MACH3, with the exception:

There are now standard absorbers which makes it possible to check if the intensity is all right with the EFFIC measurement.

Det. error : for small adjustments and only when really needed, adjust the detector position with the three Allen screws on both sides of the detector stand. Direction:

• Measure the intensity of the primary beam (see safety) with the MACH3 standard absorber with Mo : 30 kV 10 mA or Cu : 20 kV 10 mA.
• Set in the pocket terminal: WD = 1000, LL = 100, HV = low (with xxx MOVE WD/LL/HV)
• Raise the HV untill the intensity reaches a plateau (after the plateau it raises again, but that is dark current).
• Set LL = 400 and adjust the HV, so the intensity at LL = 400 is half the intensity of the previous plateau.
• Fine adjust the HV, so the intensity at LL = 400 is half the intensity with LL = 10. Then the sensitivity peak is situated at 400.
• Input HV and default  LL and WD in GONCON (values changed in the pocket terminal are not saved)

• Remove on the goniostat the largest brown plastic cover.
• Disconnect the top connector.
• On the pocket terminal: MOVE, SPEC, PHI. Then it should show: PCC ####
• Look into the interface to the Encoder board: the right one of set of boards on the left. At the bottom, in the middle of the board, there are two adjustments.
• Connect according A and adjust with the upper adjustment the pocket terminal between PCC0003 and PCC0004
• Connect according B and adjust with the lower adjustment the pocket terminal jumping between PCC7773 and PCC7774. When you don't reach this value:
• Measure the voltage between 0 V and 10V. When it is 10V then probably the ADC converter on the Encoder board is defect and a new board must be bought.
• 

Phi coarse, zero adjustment (small adjustment if TEST ALL shows a drift)

• (A change of Phi coarse zero position is uncommon. Normally it only happens when someone really repositioned the encoder)
• Pocket: 0,  move,  Phi
• Check on the mechanical dial if it is really at zero position
• Pocket: spec,  Phi,  C/F  to read PC (= position phi coarse). This should be zero +/- 4.
• If higher then loosen the three screws of the encoder (see above, red, needs a 90 screw driverº) en rotate the coarse encoder till 0 +/- 2.

• Open
• Remove the side plates of the indicators.
• Remove two screws in the indicator with an long Allen key
• Remove the cover and mount the indicator again (temporary with one screw) prevent loosing the zero position of the indicators.
• Close
• Remove the indicators
• Mount the enclosure
• Position on zero
• Mount the indicators in position zero.

Change of a cable running inside the omega axis for Phi and Kappa. This can only be done with a new or a revised old CAD4. The holes of an old CAD4 are too small to mount a new cable. Dismount the microscope support and you will see the cables:

Change of the Phi cable:

• Open the goniometer
• Position Kappa on zero.
• Remove the brown plastic cap from Phi.
• Disconnect the plug (notice the colours) and dismount the Phi unit.
• Remove the brass ring by rotating with a pointed pliers.
• Remove the indicating wheel.
• Remove the cable in the groove (encoder is the left cable) and mount the new one. It should be glued deep in the groove, so it does not touch the indicating wheel.
• Pull the new cable trough the hole, trough the centre of the goniometer to the bottom, and again trough a hole in the base upwards.
• Solder the cable to the connector or cut the old cable some distance from the connector and solder to the new cable.
• When remounting, position the indicating wheel exactly on zero.

For returning the Phi encoder/motor unit for repair it must be remounted:

• Dismounting
• Position to zero.
• Remove the largest brown cap (4 screws).
• Disconnect the connector and remove the adhesive tape from the cable (make a drawing how it is fastened, because the cable must be taped again in the same way after remounting)
• Remove three small screws close to the poles:
• 
• Slide the unit backwards.
• Mounting
• Position the Phi axis with the indicator to position zero and fix it with tape.
• Connect the flat cable to the Phi unit.
• In pocket terminal: SPEC   PHI    C/F  C/F.  This shows the course potmeter (PC) and fine potmeter (PF).
• Adjust the Phi unit encoders till both readings are zero, first course value then fine value.
• Mount the phi unit in this position as shown above very careful so the gears match. One can help this by rotating Phi slowly (>  2  MOVE   PHI).
• Fasten the Phi unit and position to zero (0   MOVE  PHI). You can try to position to exactly zero by rotating the Phi unit somewhat when the screws are still loose, but it is not really needed because Phi has a relative position which is anyway (the pin of the head) not exactly zero.

• Can only be done by experienced service men.
• 
• Remove the monochromator.
• Tube to zero degree (don't remove the tube holder).
• Remove the sliding front plate (A). You will need a square screwdriver.
• Mark the position of all parts, so you will remount it in exact the same position. When remounting check all parts and rings, to remount it in the same way.
• Remove the filter disk. This must be done with two people. One keeps the filter disk pressed against the holder, the other removes the screw in the middle.
• Tilt/remove the filter disk but be careful: behind the disk, on top, is a spring with a steel ball which will jump away. So put some paper underneath.
• Remove the shutter coil assembly with two screws right (B).
• Remount all in the same position. When mounting the filter disk put some grease in the hole and put the steel ball in, so it does not fall. The spring remains in position.
• Don't grease the shutter, because it needs special X-ray resistant grease.

When upgrading to Express or Linux software and having a LSI 11 processor board (M7270), some changes must be made : See Product Change Note 37 (ask Service).

When using VAX or PCDOS no change is needed.

With a Falcon (M8063) or Falcon+ (M7676) processor board no change is needed.

The +5V power supply is the large supply located in the left part of the Interface behind the panel with the on/off switch.

• Measure the +5V on the back of the Interface, on the computer backplane (with the many pins), on the connector pins with the thick red and black wire. It should above +4.8 V, also during start-up of the computer program (when it draws a lot of current).
• When it is much too low, the power supply is defect.
• When it is a little too low you can adjust  the power supply:
• Remove all cables from the interface except the power cord.
• Dismount the Interface and turn it up side down. You can reach a potmeter on the power supply from the bottom.
• Adjust the voltage carefully to 5.1V (not too high, because the electronics is still connected).

A single encoder can only be changed by an experienced servicemen.

A complete (encoder)unit is more easy to replace, but still needs some experience:

Theta, Omega, Kappa

• Position the axis exactly on zero.
• Fix this position with tape, on the mechanical readers (Theta, Omega: remove the side cover. Kappa: remove the brown plastic cover).
• Switch off the electronics and solder the wires to the new encoder unit, but do not yet mount it on the goniometer.
• Switch on the electronics and readout both encoders in the pocket terminal: spec,  axis,  C/F  (C = course, F = fine)
• Position the encoders with gear A on zero. First course, then fine.
• Mount the encoder unit, with the screws fixed but not tight.
• Check the backlash, by moving the internal gear B with a screw driver. In fine reading it should change 1 bit. Not more, but also not less. Give soft blows against the unit for small shifts in horizontal direction towards or away from the axis gear C
• Fasten the mounting screws
• If the reading is no exactly zero in fine (mostly), then loosen the red lacquered screws of the fine encoder and rotate the encoder a bit till the reading is zero. Then fasten the screws.
• 

Another, more complicated description can be found in an instruction (1990, see PCN-list):

• Kappa fine or coarse encoder.
• Phi drive unit (includes motor and encoders)
• Theta encoder unit.

GONCON, GCONST
 

Command code	Default
CON1	approx. 0.5868241	sin²(alpha)     (Factory installed, alpha = Kappa = approx. 50º)
CON2	approx. 0.6427876	cos(alpha)      (Factory installed, alpha = Kappa = approx. 50º)
CON3	approx. 0.0001787	cos²(89) * sin²(alpha)      (Factory installed, alpha = Kappa = approx. 50º)
THPOS	77.50	Theta positive software limit in º
THNEG	-49.00	Theta negative software limit in º
PDIST	78.50	Distance crystal - Polaroid in mm
RADIUS	173.	Distance crystal - aperture/slits disk in mm
SLIT	4.0	Manual horizontal slit in mm
APMAX	5.9	Aperture vertical maximum in mm
APMIN	1.3	Aperture vertical minimum in mm
MAXVAR	xxxx	Encoder position of maximum aperture
MINVAR	xxxx	Encoder position of minimum aperture
UPPERH	xxxx	Encoder position of upper hemisphere hole
LOWERH	xxxx	Encoder position of lower hemisphere hole
NEGSL	xxxx	Encoder position of skew slit, negative
POSSL	xxxx	Encoder position of skew slit, positive
VSLIT	xxxx	Encoder position of vertical slit
HSLIT	xxxx	Encoder position of horizontal slit
HOLE	xxxx	Encoder position of open hole
Attenuator filter factor and X-ray tube: see command WO / WI

GONCON, CASPAR
 

Command code	Default
HV	approx. 576	Detector high voltage in volt : see Adjustments
LL	200 (Mo) or 100 (Cu)	Detector low level
WD	500 (Mo) or 600 (Cu)	Detector window (LL + WD = max. 1275)
DT	0.8300	Dead time in us
BR	9600	CT port (Terminal) baudrate (not Host)
PA	2.	Axes positioning accuracy (in encoder digitization steps). A positioning command only finishes when the end position (or end of a scan) is within this value.
MT	24	Motor gain for Theta
MP	26	Motor gain for Phi
MO	24	Motor gain for Omega
MK	24	Motor gain for Kappa
MD	24	Motor gain for Dial
FL	NO	Phi limit switch present
FL	NO	Special collar software present
FL	NO	Cryostat boundary software wanted
FL	NO	Turbo goniometer
FL	NO	Rotating anode. If NO: then a remote controlled HV generator is expected, like the FR590.
EM	60.0	HV generator emission trigger level in mA (normally not used)

 
 

LED's and switches

LED's
 

Mains	Run
+5V (digital)	Indication of the halt switch (not indication of processor running)

RS232 communication lines
 

flash	flash	flash	Flash when receiving data
PT	CT	CC
on	flash	flash	Flash when transmitting data
Pocket  terminal	Terminal	Host  computer

Switches
 

Mains	Power
Run	To stop/start the target program. Don't use this. Use mains to start-up. Normal working position : down.

 
 

Specifications

 
Goniometer

Anti-collision

• Anti-collision software.
• Axes maximum position switches. Turning back is possible.
• Collision switches on both collimator holders.

X-ray optics

Detector

Goniometer heads
 

Height	49.0 mm
Distance ring	14.96 mm
ECON head	X, Y: ±1.5 mm Z: 8 mm
XYZ head (option)	X, Y: ±2.5 mm Z: 8 mm
Eucentric head (option)	X, Y: ±2.5 mm Z: 3 mm angle: ±15°

 

Safety interlocks

• The collimator is not in the right position.
• The monochromator or X-ray port is not in the right position.
• The shutter-open lamps are defect.
• The radiation enclosure is not closed.
• When using a rotating anode: the goniometer is not properly placed in front of the X-ray port.

• The shutter does not close.
• The high voltage cable is not connected to the X-ray tube (indicated by a link, attached to the cable and connected to the tube holder).
• The X-ray on lamp is defect.

The system is supplied with one override, which is only allowed to be used during technical maintenance (see safety rules).

• Connecting a flashing Open-beam lamp to the enclosure connector on the goniometer connector overrides the radiation enclosure safety. When the lamp is defect the override is cancelled.

With a X-ray generator all safeties are handled by the generator, except the shutter safeties: collimator and beam stop.

Safety signals

• Shutter-open lamp (red) : illuminated when the shutter is opened or is not fully closed.
• Shutter-closed lamp (green, only with sealed tube): illuminated when the shutter is fully closed.
• Open-beam lamp: flashes when the radiation enclosure safety is overridden.
• X-ray lamp: illuminated when X-rays are generated.

Safety with power off

Safety demands that circuits are automatically in a safe position when they are out of order. So during power off, the goniometer Interface and the X-ray high voltage are switched off by the safeties.

Connections

Programmable IC's
 

Motor generator board	IC25	600.25A	For LSI-11
0546.600		MOT1B	For Falcon and later.  Can also be used in  older equipment
Radiation detection board.      0546.602	IC23	602.23A
Encoder readout board	IC19	605.19A	Probably for LSI11
0546.605		ENC3A	For Falcon/Falcon+
	IC5	605.05A	For old version ADC
		ENC4A	Last version from 1984 for new version ADC (PCN 26)
	IC6	605.06A	For old version ADC
		ENC5A	Last version from 1984 for new version ADC (PCN 26)
Personality module / QLC brd.	IC1  IC2	606.01/2B  606.02B	For LSI-11 (Does not work with DOS)
0546.606/616		PMQ1C  PMQ2C	For Falcon, with all software
		PMQ1E  PMQ2E	For Falcon+, Falcon, with all software
		PMQ1F  PMQ2F	For LSI-11, with DOS and VMS
		PMQ1G  PMQ2G	For Falcon and Falcon+: newer 4 kB type. With hardware change (see instruc. 15 May 1995)
		PMQ1H  PMQ2H	For LSI-11: newer 4 kB. Needed for Linux/Express. This PROM is needed when using Linux/Expres with hardware change (see PCN 37)
	IC3	606.03A	For LSI-11
		PMQ3B	For Falcon
	IC4	606.04A	For LSI-11
		PMQ4A
Radiation detection board       0546.612	IC1	RAD2A	Can be used in all equipment
Bus Interface  board	IC4	BUS4A
0546.604/614	IC12	604.12A	For LSI-11
		BUS1D	For Falcon/Falcon+
	IC40	606.40A
		BUS8A	For new version 0546.614. Can also be used in older equipment
	IC42	BUS9A	For Falcon/Falcon+