17
UBI EasyCoder 401 –Technical Manual
SETUP PARAMETERS, cont'd.
TheDetectionfacilitiesareusedtoadjustthelabelstop/blackmark
sensor (LSS) and to control the paper feed.
LSS Adjustment:
TheLSSisaphoto-electricdetectiondevicethatcontrolsthepaper
feed. Situated inside the printing mechanism, it detects the front
edgesof the labels, slits intickets or tags, ortherear edges of black
marks at the back side of the paper web.
Iftheprinterissetupfor “Label(wgaps)”,“Ticket(wgaps)”,“Fix
length strip”, or “Var. length strip”, a narrow beam of light is
emitted from the upper part of the LSS and received by the sensor
in the lower part. Non-transparent paper will block the beam
completely, whereas semi-transparent backing paper between la-
belswillallowsomeofthelighttopassthrough.Adetectiongapin
the ticket web causes no interference at all. An out-of-paper
condition is assumed, when no interference to the beam has been
detectedwithinafeedlengthcorrespondingtothedistancebetween
the dot line on the printhead and the sensor.
Whentheprinterissetupfor“Ticket(wmark)”,thelightisemitted
from the lower part of the LSS. The beam can be reflected back to
the receiver by the white paper at the back of the web. If the beam
hitsablackmark,practicallynolightwillbereflectedback.Anout-
of-paper condition is assumed, when no reflected light has been
detectedwithinafeedlengthcorrespondingtothedistancebetween
the dot line on the printhead and the sensor.
Obviously,itisimportantthattheprinterissetupforthecorrecttype
of media (see “Media Type” later in this chapter) so the firmware
can interpret the signals correctly.
TheLSScan be moved max. 50mmsidewaysacrosstheweb.The
inneredge of the handle indicatesthe lateral position ofthesensor.
The LSS is automatically fine-adjusted when a Testfeed operation
isperformed.Moreover,theLSSemitterscanbeadjustedinregard
oflightintensityintheSetupMode(accessibleviaUBIShell)orby
meansofsetupfiles,andtheLSSreceivercanbeadjustedbymeans
ofapotentiometerontheCPUboard(seethechapter“Electronics/
Potentiometers”).
Ifthe printer works as expected, there is noneed to adjust the LSS,
butiftheprinterstartstofeedout labels or tickets in an unexpected
manner, check that the sensor is properly aligned in relation to the
web and that it has not become dirty. Perform a few Testfeeds to
makethesensorauto-adjust.Iftheerrorremains,proceedaccording
to the description of the Setup Mode in the UBI Shell Standard
Startup Manual. Only as a last resort should the potentiometer be
adjusted. Continued!
Detection
• LSS Adjustment
• Feed Adjustment
Emitter and
Receiver
Emitter
TheupperpartoftheLSSisalightemitter
for labels, tickets and strip, whereas the
lower part contains both a receiver and
an emitter for black mark detection.
Handle
Theinneredgeofthehandleindicatesthe
position of the LSS.