Pitney Bowes DM300c Service Manual page 47

3.4 Envelope/
Tape Transport
✍
TIP: See section 3.10
for DM475 differences
and specific theory.
DM300c/DM400c/DM475 Service Manual (SV61801 Rev. D)
Sequence of Operation (cont'd)
Debit Request
Mailpiece
Figure 3-17 Debit and Print Timing
4. Once the system has confirmed the debit within the allotted time, it is-
sues the print start command and prints the indicium (meter stamp).
FS1 senses the following mailpiece which is approaching FS2.
5. FS2 detects the lead edge of the next (following) mailpiece and the sys-
tem calculates whether the gap between pieces is correct.
The system logic is designed to maintain a consistent gap between
pieces of 11 inches from lead edge to lead edge. The gap between
pieces is defined as envelope length N + gap X = 11". In other words, if
envelope length is 5 inches, the gap between the trailing edge of piece
one and the lead edge of piece two is 6 inches, for a total of 11 inches.
If a series of #10 envelopes were run, the trail edge to lead edge gap
between pieces would be 1.5 inches (9.5 inches + 1.5 inches = 11 inch-
es).
The system logic monitors the state of FS2 and PS1, the mailing ma-
chine's lead edge detector. If a piece does not arrive at PS1 within a
predetermined time, an error is declared.
6. The first envelope arrives at the print finish position and is driven into
the stacker by the output rollers. The following mailpiece blocks FS2 as
it approaches PS1.
7. As the leading piece exits, the following piece blocks sensors PS1, PS2
and PS3, at which point the system logic assumes there is no transport
fault (misfeed, jam or skew) and initiates the meter debit. The process
repeats (steps 4 through 7) as required.
3 • Theory Of Operation
PS3
Debit Complete
110/120 msec
(3 inches)
Print Head
Generate Data,
Initiate Printing
3-17