Setting up current control for Head Controller (HC) Version B

1. Run FocusActLin.spt.
2. Ensure that the travel is smooth and the hysteresis is minimal. The lines should be very close together.
3. Find the point of inflection on the FocusActLin.spt output. The point of inflection is the current at which the slope of the graph changes from decreasing to increasing. See the sample graph (Point of Inflection = 0.875).
4. To generate the lookup table, enter foc gen lut in the Splot terminal.
5. Enter foc cal svf [I-O.1] [I] [BW1], where I is the current at the point of inflection, and BW1 is the requested BW, as indicated in the following table:

   DPI	BW1	BW2
   1200	130	110
   2400	150	130
   2540	150	130
   3200	150	130

   For example, for 2400 dpi the command would be: foc cal svf 0.775 .875 150.
6. Run LposVLpos.spt. Ensure that there is no ringing in the response and that the travel is smooth. The oscillation at the top and bottom of the graph should be minimal.
7. Enter foc cal svf [I-O.1] [I] [BW2] in the Splot terminal.
8. Run LposVLpos.spt. Ensure that there is no ringing in the response and that the travel is smooth.
9. If everything is working well, enter foc save lut in the Splot terminal, followed by foc save svf.
10. If required, enter >redirect disable in the Splot terminal.

If any of the scripts or commands fail, contact the Response Centre.