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SAMLight Manual > Option MOTF > Endless MOTF

Endless MOTF
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SAMLight provides the option to do endless cutting or endless looping, giving the possibility to fold a polyline in order to pre-compensate the MOTF movement.
For these Flash-only-features (only for USC-2/3), the SAMLight Option Flash and Option MOTF are required. Then, the job needs to be prepared in the following way:

1.First, the unfolded polyline is created in SAMLight. The entity must not be more than one single polyline (no jumps allowed). The Y-coordinate of the first and of the last point of this polyline must be identical, the X-coordinate of these two points must be different.

2.Then, this polyline is folded

a.either while being exported as CNC with the advanced option of endless cut or endless loop (File → Export, choose GCode Files (*.cnc) as file type and open the Advanced... dialog; see figure 366)

b.or while being saved to the Flash memory. (Extras → Flash, activate the checkbox SJF → CNC → UNF and open the settings dialog on the right; see figure 366).

3.If the polyline was folded by the export function of SAMLight, this CNC file can then be loaded to the USC card (e.g. per FTP server) and convert to UNF file. It can also be imported into SAMLight for the purpose of illustration (see figure 365).

 

In Endless Cut and in Endless Loop modes, the target speed should be close to a nominal MOTF speed V(MOTF). For MOTF speed variances, a look-up-table for the scanner speed and for the laser power is provided for up to 16 controller cards. Please note that the outline of the polyline can be larger than the field size of your scanner along the MOTF direction before the convolution has been executed. If you want to save the values of the CNC export in your job file, check File → Job Properties... → MOTF Multiplier, Save in Job / Load from Job. To save the setting for the look-up-table (see illustration in figure 367) for scanner speed and laser power, you have to select the polyline you want to mark. Then, go to File → Export, choose GCode Files (*.cnc) as file type and open the Advanced... dialog.

EndlessMOTFcncExport

Figure 365: Illustration of Endless Loop: a) A sine curve with an outline larger than the field size,
b) after CNC export the sine curve is folded to a closed form which fits into the field size and can be marked endlessly.

note

In this feature the vector compensation is not based on MOTF encoder values. Instead the vector calculation is pre-calculated by folding the polylines. This is done by generating the *.UNF job for a nominal speed and will be adjusted by internal override parameter which can be defined in lookup tables for speed and laser power. However, the internal override procedure is not done in real time but at the beginning at each job. If the belt speed is not constant this functionality will lead into small distortions of the vectors.  

The following endless MOTF dialog (figure 366) can be reached via Extras → Flash, activation of the checkbox SJF → CNC → UNF and opening of the Settings dialog on the right.

EndlessMOTFDialog

Figure 366: Endless MOTF Dialog

Head Number: Chooses the card number. For single card applications, choose '0'.

Enable Endless Cut: Folds the polyline(s) by the nominal MOTF speed V(MOTF).

Requirements of the polyline(s): The entity must be a single polyline or series of polylines (no jumps between vectors are allowed).

V(MOTF) in m/min: Sets the nominal MOTF speed. This speed is used for the folding of the vectors.

Enable Endless Loop: Folds the polyline into a closed form. Laser will be left on all the time during marking.

Requirements of the polyline: The entity must be a single polyline (no jumps between vectors are allowed), the Y-coordinate of the first and the last point of the polyline have to be the same whereas the X-coordinates of these two points must be different.

V(MOTF) in m/min: Sets the nominal MOTF speed. This is used for calculating the scanner speed if override speed is disabled.

Keep polylines start position: When disabled, the folded polyline will be centered. When activated, the start position of the polyline will not be changed. In this case, the start point of the polyline needs to be within the valid field.

External Trigger each loop: The USC card waits for external trigger via OPTO_IN_0. This can be used in combination with endless cut.

Loop Count: Define the number of loops the polyline will be marked, type -1 for endless marking.

Loops in Buffer: Buffered jobs are used to avoid gaps in the marking result, but buffered jobs will not be updated by OP / OS values.

Job start offset: A single MOTF offset is added at the beginning of the job. It is not included in the loop and only included if not in trigger mode.

Enable OP, Enable OS: For MOTF speed variances a look-up-table for scanner speed and laser power can be defined. This can be done by defining an lower and upper limit of the MOTF speed. In the range between Vmin and Vmax three nodes are set equidistantly, refer to the picture below. If Override Laser Power (OP) / Override Scanner Speed (OS) is enabled the laser power / scanner speed will be overwritten at the beginning of each job.

linear OS: Uses the nodes of OP for OS as well.

MOTF Channel: Defines the source of the MOTF encoder signal: 0 = MOTF-Channel 0 at the 37 pin connector, 1 = MOTF-Channel 1 at the 40 pin extension connector.

V < Vmin: Defines a constant scanner speed / laser power if MOTF speed is below the range of the look-up-table. If disabled, Vmin is used instead. The internal minimum override value is 20%, so do not use smaller values.

Vmin, Vmid, Vmax: Nodes of the look-up-table. Speed values in [m/min], override value in [%].

V > Vmax: Defines a constant scanner speed / laser power if MOTF speed is above the range of the look-up-table. If disabled, Vmax is used instead.

Gain: All nodes values of the look-up-table will be multiplied by this gain.

Offset: An additionally offset value can be applied to all node values.

The following figure illustrates the look-up-table of speed and power values for endless MOTF.

These setting for the look-up-table for scanner speed and laser power can be saved after selection of the polyline you want to mark via File → Export, choose GCode Files (*.cnc) as file type and open the Advanced... dialog.

EndlessMOTFDiagramm

Figure 367: Illustration of Speed- and Power-look-up-table in endless MOTF