Service manual

3 • Theory Of Operation
DM300c/DM400c/DM475 Service Manual (SV61801 Rev. D)
3-45
3.10 DM475
Feeder/WOW
Theory
The DM475 consists of two physical sections which are mated together at
install:
• Printer/Base
- Printer
- Main Board
- Mail and Strip Tape Transport system
- Power Supply
- User Interface
- Postal Security Device (PSD)
• Feeder/WOW
- The WOW (Weigh on the Way) base assembly and load cell.
- The Feeder/WOW main board, which contains all of the functional-
ity of the DM400c/DM450c feeder board, and additionally provides
motion control for the WOW unit. The Feeder/WOW main board pro-
cesses the data from the load cell and SBR Sensors and communi-
cates directly with the main board using USB.
- Mail transport system.
WOW Operation
• The WOW (Weigh on the Way) is an internal; in-line mail classifier option that
automatically weighs and rates mail pieces then transports them to the printer.
• The system evaluates the weight and shape of a mail piece on its tray
for the postal weight breaks of the user-selected class. After determining
the weight and shape of the mail piece, the appropriate postage value is
sent to the meter.
• The WOW weighs and rates mail pieces from 1/5 ounce to 16 ounces.
The load cell is a small analog device that is fastened between two thick
aluminum base plates. The aluminum casting that connects to the top of the
load cell is similar to the platform of a weigh scale. The load cell is attached
to the upper and lower castings. The load cell, with its upper and lower cast-
ings, is the actual assembly that service replaces if a load cell is faulty.
The rest of the WOW unit is attached to the load cell assembly and includes
the drive, motor, sensors and encoders. The complete WOW unit bolts into
the tub of the DM475 to the right of the feeder unit.
When a Shape-Based Rating (SBR) class is selected by the operator, the
system will use the shape of the media in addition to the weight to deter-
mining the price. The SBR components include the width sensors, the
thickness encoder, and the three deck sensors used to measure the media
length (FS1/WS1, WS2, WS3).
WOW units used on other mailing machines (DM800i, DM1000, etc.) have
belts that drive the media from above. The DM475, however, has a new WOW
design that uses a drive belt below the media, and the idler rollers above.
✍
TIP: The DM475c
mailing system uses
the existing DM400c
autofeeder hardware,
print engine, modem,
USB and serial ports,
meter PSD, and tape
feeder.