Pitney Bowes DM300c Service Manual page 50

3 • Theory Of Operation
3.4 Envelope/
Tape Transport
✍
TIP: The DM475 uses
the existing DM400c
autofeeder hardware,
print engine, modem,
USB and serial ports,
meter PSD, and tape
feeder.
✍
TIP: See section 3.10
for DM475 differences
and specific theory.
3-20
Sequence of Operation (cont'd)
Operating Sequence—Tape. For the discussion that follows, refer to the
Tape Print Sequence diagrams (Figure 3-20) on the following two pages.
This discussion assumes that the user has properly loaded tape strips in the
chute, the postage amount is set and the system is nominal.
1. When the user presses the TAPE button, the print carriage moves into
the print position as described previously and a mild purge is performed
if necessary
2. When the print carriage is in the print position, both the tape and the
feed transport motors start. The tape feeds down, blocking sensor PS1
and enters the nip of the feed rollers.
3. When the tape strip has fed 30mm beyond PS1 as calculated by the
distance encoder, the system logic stops the tape motor.
4. The tape feeds to PS2/PS3 where skew detection is performed (3C00
Only). The meter debit process is initiated by PS3. As noted earlier, all
three transport sensors must be blocked by the tape strip and the debit
process must occur successfully within the 110/120 msec window as
illustrated in Figure 3-17.
5. When the debit (data generation) is complete, the transport drives the
tape strip to the print station.
6. When the tape strip arrives at the print start position, the print head
heats and fires, printing the indicium (meter stamp).
7. PS1 senses the trail edge of the first tape. If a second tape is called for,
this detection starts the tape motor.
8. The first tape reaches the print finish position and is ejected by the out-
put (exit) rollers.
9. The second tape feeds down from the chute, blocks PS1 and feeds into
the nip of the first transport rollers. When the tape lead edge is 30 mm
beyond PS1, the system logic stops the tape motor and the process re-
peats from step 4 to 9.
DM300c/DM400c/DM475 Service Manual (SV61801 Rev. D)