MARKEM Cimjet RFID, Руководство по эксплуатации и обслуживанию

Страница: 102 / 158

SECTION 6 Preventive Maintenance Guide
6–8
m
®
0855904enb 4/05
6.3 Tag Gap Optic
An optical slot sensor is used to determine if the tags are stopping in
the correct position. Infrared light is passed from a transmitter to a
receiver on the ends of the sensor. The tags are run through this
sensor, and the amount of light passing through the tags or tag gap
is recorded as a voltage change and stored as a digital figure which
is used by the processor.
Cimjet RFID uses stepper motors and will step these at either
8 steps/mm or 12 steps/mm. The backing web in the gap between
tags will allow more light to pass through than the backing web and
tags together. These voltage levels are used to determine if a tag,
backing web and no tags, are present in the sensor.
An example of how this process works is described below:
Tag size 100mm (3.94”)
Tag gap 3mm (.118”)
Stepper motor 8 steps/mm
When the Cimjet RFID feeds datum labels, the processor will record
a constant voltage level for 800 (100mm [3.94”] x 8) steps of the
stepper motor and then record a rise in the voltage level for 24 steps
(3mm [.118”] x 8).
This is used to inform the processor when to start and stop feeding.
If these levels start to vary, the machine will initiate a tag feed fault.
If the tag gap happens to stop in the gap sensor, this will cause tag
feed problems. A second hole position for the gap sensor is
provided in the base plate for this condition.
Two possible optic positions are provided. The standard position is
the farthest position away from the beak.
If the gap optic has to be moved, the OPTIC ADJUST parameter
should be set accordingly to minus 100 (-10mm)
After adjustment, reset the gap optic.
The gap threshold voltage is the transition voltage where the
processor senses that it is transitioning from a tag to a gap or vice
versa. The setting for the threshold voltage should be at the
midpoint of the gap voltage and the label voltage.