When the instrument is waken up, it goes through a initializing sequence. It drives the mechanism through the homeswitch, sets the encoder to zero and then drives a certain offset value that is know in software. The current system has quite a bit om mechanical backlash in the worm/wheel drive. It is around 40 microns. Between two fibres there is an offset of 135 microns. This needs further investigation to see whether we can improove this.

sequence: 

• brakes loose on X and Y shaft
• initialize off axis probe
• initialize Z axis
• initialize Theta axis
• gripper operates 3 times (pneumatically open and close)
• initialize X axis
• initialize Y axis 

Check orthoganality theta axis after initialize.

It is very important that the theta rotation is orthogonal with the X- and Y-axis of the robot. This is best measured with a straight ruler in the gripper jaws. It is best to put the instrument on the manipulator (trolley that can be moved) so the instrument can be put horizontal, this to eliminate gravity working on the ruler.

• Wake the robot.

• Go to extended mode ( extended / pxc682m)

• move Z axis to 4000  (to be able to clamp ruler in the jaws.

• Carefully place the ruler in the jaws then type gripper closed.

• Now check if the ruler is orthogonal with the X and Y slides.

• Another way is to measure the distance from the ruler to both edges of the robot frame.

• If there's a misalignment move the robot in small steps until your happy with it (tmove n)

• Read the theta position tellpos, write down this value, it has to be changed in the software.

• Type restricted to go back to normal mode.

Now to change the value in the software you have to do the following: You have to copy the af2def file to a new file. This way it is possible to change parameters in this file without corrupting the original af2defs file. Once your fully happy with the changes you can copy this file to the af2defs file.

• Type stopall

• logout

• login

• username: sfdev

• password: 

• dir (will show directories)

• chd appsource    (change directory)

• dir

• copy-r afsdefs.h af2defs.new     (this will copy the afdef file to a new one so you can change values without immediately ruing the original one)

Now the new file, which is identical to the af2defs file, is ready to be modified. For this you can use different editors in this manual we describe vi.

• Type vi

This opens the editor. Now you can make changes to different parameters. The parameters have to be updated, that means that the current value will be remarked out and the new one will be made active. 

vi commands

• :q!        (quit without save)

• :w         (quit and save)

• i            (to go to insert mode)

• space    (to insert space)

• ctrl {     (to exit insert mode)

• escape  (to exit insert mode)

• x            (to delete one character)

• dd          (to delete one line)   !!!

• del_af2defs    (to delete a file from directory   

To change any values in the af2 params.dat file 

• chd datafiles

• chd af2params.dat

• vi af2params.dat

• x             (delete one character)

• i             (to insert mode)

• change value

• escape    (exit insert mode)

• :wq     (to write and quit)

• Reboot micro

Once you are happy with the changes you have to make sure that the previous value is remarked out. Therefore you have to take away the # in the beginning of the line. Look for examples on the previous lines.

Now before you change the  updated file to the af2defs.h  file you should make a backup file just in case?!

copy-r af2defs af2defs20020816.h     (the last file is now the backup file with the original values in it)

Now change the af2defs.new to af2defs.h       copy-r af2defs.new af2defs.h

Now rebuild the control software using the command    make

watch the make build the software. If there's any failures it is almost certainly a syntax error in your edits of af2defs.h

Reboot the VME and wake the instrument it should have been changed now.
 
 
 

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 Last updated 12 january 2003 by Michiel van der Hoeven