Paper Pre-End (Paper Low) Sensor Option - Hengstler eXtendo X-56 Operating Manual

eXtendo® Thermal Printer Family
common is the reflex or reflective sensor, where the light source and detector are located
on a single chip. Basically, the light strikes the white paper surface and reflects back into
the sensor. If enough light reflects to activate the sensor, the printer concludes that paper
is present. If there is not enough light reflected, the printer assumes that this area is black,
meaning the printer is on a black mark or the printer is out of paper. There are six (6)
different possible positions for this sensor in the X-56 and ten (10) in the X-80. Half of these
positions sense the coated side of the paper, while the other half sense the back of the
paper. The positions of these sensors are detailed in the Paper section of this document.
The eXtendo® can also use a through-beam sensor in OEM applications. This type of sensor
has a light source on one side of the paper and the detector on the other side of the paper.
When the light is blocked and cannot reach the detector, the printer concludes that paper
is present. When the light does reach the sensor, the printer concludes that there is no
paper present.
The through-beam sensor can also be used in a manner similar to a Black Mark sensor.
Instead of a Black Mark, a hole is used in the paper. The through-beam sensor is located on
the centerline of the paper path. This is the only location it may use.

3.6.2. Paper Pre-End (Paper Low) Sensor Option

When ordered with the Paper Pre-End Sensor option, the eXtendo® will be shipped with a
paper pre-end sensor to be mounted by the customer. The sensor is a reflex type, meaning
that it senses paper by bouncing light off the paper and detecting its reflection. The sensor
is equipped with a 300 mm long cable to allow flexible mounting by the customer, and the
sensor itself is mounted on a small printed circuit board with a hole to be used for
mounting it. Simply mount the sensor where it will detect paper low (it is often mounted
facing the side of the paper roll, so that as the diameter of the paper roll decreases, it
eventually loses the reflection of the light and changes state), and plug the PPE sensor into
the upper sensor connector on the control board. While the exact distance of the sensor
from the paper varies from application to application, it is typically 2-5 mm for optimal
sensing.
If the printer with a paper roll holder is ordered, the sensor comes pre-mounted to the
paper roll holder and with the sensor connector plugged into the eXtendo® controller
board. Figure 5 below shows the PPE sensor itself, while Figure 6 is the input circuit to the
Paper Pre-End (Paper Low) input.
The lower sensor connector is for an Auxiliary Sensor, which can be mounted as desired by
the customer. The status of this sensor or it input voltage reading will be reported when
the printer's status is requested via the interface. The Auxiliary Sensor connector is located
below the Paper Pre-End (Paper Low) Sensor connector.
Figure 6 shows the input circuit for these sensor connectors (Fig. 6 represents the circuit for
either the Paper Low or Auxiliary Sensor; these two inputs are wired identically). Please
note that each sensor input can have two connectors, a second one on the wheel side of
the printer. The Paper Pre-End (Paper Low) Sensor connectors are designated CN6 and
CN6', while the Auxiliary Sensor connectors are CN8 and CN8'.
Note: Only one connector of each pair (for example, CN6 and CN6') should be connected at
one time.
Part No. D-684-124 Mod. No. 4 270919 HW1 page 12 of 33