Intermec EasyCoder PF2i Service Manual page 92

Chapter 7—Print Mechanism
Working Principles
84
The label stop sensor serves a number of purposes, depending on how
the printer is set up in regard of media type in Fingerprint and IPL
respectively:
Label (w gaps)/Gap
A beam of light is emitted from the diode in the lower part and received
by the sensor in the upper part. The fi rmware detects the front of each
label, that is, when the light is completely interrupted by the opaque
label, as opposed to the semi-transparent liner in the gaps between labels.
If no label has been detected during a media feed corresponding to more
than 150% of the set label length, a "next-label-not-found" condition is
assumed. If a renewed print operation gives the same result, an "out-of-
paper" condition is assumed.
Ticket (w mark)/Mark
Normally, a beam of light is emitted from the diode in the lower part. The
beam is refl ected back to the sensor in the lower part by the white media,
or is absorbed by a black mark. The fi rmware detects when the front edge
of a black mark passes the sensor, that is, when light starts to be absorbed.
If no mark has been detected during a media feed corresponding to more
than 150% of the set ticket length, a "next-label-not-found" condition is
assumed. If a renewed print operation gives the same result, an "out-of-
paper" condition is assumed.
By switching the cables from the upper and lower part of the LSS on the
CPU board, black marks on top of the media can be detected.
Ticket (w gaps)/Gap
The light is emitted from the diode in the lower part and received by the
sensor in the upper part. The light will either pass uninterrupted through
a detection gap in the media or be blocked by the non-transparent ticket.
The fi rmware detects the rear edges of detection gaps, that is, when the
light starts being interrupted. If no ticket has been detected during a media
feed corresponding to more than 150% of the set ticket length, a "next-
label-not-found" condition is assumed. If a renewed print operation gives
the same result, an "out-of-paper" condition is assumed.
Var. Length Strip and Fix Length Strip/Continuous
The light is emitted from the diode in lower part and received by the
sensor in the upper part. The beam will either be blocked by the media
or be completely uninterrupted when the printer runs out of continuous
stock. The fi rmware assumes an out-of-paper condition if the light has not
been interrupted within a media feed corresponding to 150% of the set
length.
Intermec EasyCoder PF2i, PF4i, and PF4i Compact Industrial—Service Manual