EdgeGrooveQuantum800.spt is used to determine the best drum position for the plate edge detect sequence on a Lotem 800 Quantum. This script is supplied by the Thermal 2 group.

This script requires the following:

• There should not be a plate loaded. If a plate is laoded, it must not cover the drum at the carriage = 20 mm area.
• The host controller is assumed to be an MCE.

Note: The carriage position used has been selected to avoid confusion with the vacuum grooves in the same area.

How this script works:

Two passes are run, one with the focus lens extended and the zstage forward and one with the focus lens contracted and the z-stage back. This way it covers the two possible extremes for a given head install.

To create the worst case conditions, the focus laser transmitter is turned on at full power and the focus receiver is at full gain. Thus the focus SUM signal will rise to saturation as fast as possible.

The resulting graphs represent the absolute limits possible for a given head install on a given machine. Select the operating drum position for edge detect in the middle of the O.K. area.

Note: There is an example output graph below.

When to run this script: Anytime a TH2 head is installed, or its mounting is adjusted, on a Quantum 800 engine. If you ever have troubles with image shifting in the subscan direction and towards the home position.

Instructions:

1. Run the script.
2. Enter the best drum EPOS (the drum position midway between the no (or little) SUM signal region for the two cases). For example:
   

   QUANTUM>> set edge
   PRM edge parameters:
   Group        Parameter       Active             Default            Units
   ---------------------------------------------------------------------------
   edge         DrumPos         82.800             0.000              degrees 
   *** Command Complete
   QUANTUM>> set edge drumpos 83.16
   E PRM:     'edge DrumPos' changed from 82.800 to 83.160 degrees
   'edge DrumPos' changed from 82.800 to 83.160 degrees
   *** Command Complete
   QUANTUM>> set edge
   PRM edge parameters:
   Group        Parameter       Active             Default            Units
   ---------------------------------------------------------------------------
   edge         DrumPos         83.160             0.000              degrees
   *** Command Complete