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LabVIEW drivers - CAT - Liquid Handling CaRo XYZ Autosampler - Testrun


CAT - Liquid Handling CaRo XYZ Autosampler - Testrun

This webpage describes a test of the autosampler in a laboratory setup. The purpose is to show that a series of vials - 105 sets of 6 vials - can be filled and that moving from one set of vials to the next set remains accurate all the time.
In the setup there are 5 trays, each with 7 rows of 18 vials. The following picture illustrates the layout: 5 trays for 7x18 vials each

Move to...

The basic movement for the needles that will be used to fill the vials is straightforward: move up, move to the next set of vials, move down. Moving to the next set of vials is based on the position for the first set of vials (X0, Y0) and the distance between 2 sets of vials in the same row (dYsets), between 2 rows (dXrows) and between 2 trays (dXtrays).
There are 2 simple formulas to calculate the X- and Y-coordinates for each selected (Nth) set of vials: X = X0 + ((N-1) div 3).dXrows +((N-1) div 21).dXtrays

here x represents the incoming N, the outcome is the X-coordinate Y = Y0 + ((N-1) mod 3).dYsets

here x represents the incoming N, the outcome is the Y-coordinate In this particular case the geometric parameters are as follows: X0 = 180
dXrows = 150
dXtrays = 30
Y0 = 300
dYsets = 900
The orientation of the Y-axis can be altered (e.g. near becomes far) by using the alternative formula: Y = Y0 - ((N-1) mod 3).dYsets

here x represents the incoming N, the outcome is the Y-coordinate In this particular case there is one change in geometric parameters: Y0 = 2100
In caro_position.vi select 'Orientation'=1 for the first method to caltculate the Y-coordinate and 'Orientation'=2 for the second method.

Description of the test vi

The test vi is a continuous loop which will:

  • lift the needles
  • randomly select a set of vials (a number between 1 and 105)
  • calculate the X- and Y-coordinates
  • move to the appropriate location
  • lower the needles
  • loop back if not stopped

Testresult

After more than 210 movements the sampler remains in-line with the vials.
Because 210 randomly selected locations cover a greater distance than 210 sequential locations and because after having moved to 105 sequential locations the autosampler has to return to the first location or even to the reference location, it is assumed that in practice the autosampler will perform as expected.

Downloads

support files
caro_position.vi
This vi calculates the X- and Y-coordinates for set N of vials.

caro_move_sub.vi
This (sub-)vi moves the X-, Y-, or Z-'arm' to the desired position.

main program
caro_testrun.vi
This vi continuously moves the 'arms' to a randomly selected set of vials.

See also

Connecting the autosampler..


Bart Boshuizen, 2004/12/22

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