50Ms Pause After Each Line - NCR 7158 Owner's Manual

6-4 Chapter 6: Communication Interface
If the application sends data at 9600 baud and pauses between lines for
as short a time as 50 milliseconds, the printer will never be able to print
at full speed. However, if the application sends data at 19.2 K baud and
does not pause between lines, the printer will be able to print at its full
speed of 2400 lines/minute. The table below shows that with a pause
of 50 milliseconds after each line, the transmit time equals or exceeds
the printer process time, slowing down the printer, regardless of the
baud rate.

50ms Pause after Each Line

Characters/Line Lines/Receipt
20 20
20 40
44 20
44 40
* Process Time is the time it would take the printer to process the data
if all transmitted data was present. (It is not the time it takes to print
the receipt.)
Example: 20 characters/line, with 20 lines = 0.5 seconds process time
for the printer. It takes 1.2 seconds to send the data to the printer at
19.2K-baud speed with a 50ms delay after each line. Thus the printer
would have to wait 0.7 seconds longer to receive the data than it could
process it if no delays existed and the transmission speed were faster.
The next table shows that with no delay between lines, the transmit
time is much less than the process time, allowing the printer to print at
full speed.
Transmit Time
(19.2 K Baud)
1.2 Seconds
2.4 Seconds
1.44 Seconds
2.88 Seconds
Process Time*
0.5 Seconds
1.0 Seconds
0.5 Seconds
1.0 Seconds