Panasonic FP-D250 User Manual page 610

PCM (Pulse Code Modulation) One of the most common ways of converting an
analog signal to a digital signal. This is done by sampling the signal and coding the
sample. It usually samples at 8,000 times per second; each sampling representing
8bits. This produces a transmission rate of 641Kbit/s, with the traffic on the line in
interleaved data format. At the receiving end, the interleaved signals are separated
and converted back to analog.
Phase Modulation One of the three ways of modulating or altering a signal so that
it is able to carry information. The other two are amplitude and frequency modulation.
Phase modulation is used in high speed modems.
Polling Method of controlling terminals on a multi-point line by which a computer
acting as master calls or polls each of the terminals in turn to find out if they have any
data to send. This access method is used in star topology networks but is generally
being superseded by the preferred interrupt method.
Port A computer interface capable of attachment to another device, such as a modem
for communicating with a remote terminal, or, if the port is within a hub, to a workstation.
Processor Indicates the manufacture and model number of the printers processor,
sometimes referred to as a microprocessor. The processor is the brains of the printer.
The number of bits in the processor relates to the amount of data the processor can
process at once, and megahertz (MHz) indicates the speed at which data is processed.
Many of the processors in todayís printers are RISC *reduced instruction set
computing) processors, which are designed for faster processing. Note that some
printers are host based; that is, they use the host computers CPU to perform
processing some may require a that a special processor be installed in the computer.
Because they lack a processor or possess only a very scaled down version of a
processor, host based printers are referred to as dumb printers.
Proportional Spacing Printers with proportional spacing allow the horizontal space
called the pitch to vary depending on the letters width. Opposite of monospacing.
PPP (Point to Point Protocol) An addition to the Internet protocol suite to help connect
devices where dissimilar transport protocols exist, for example for the transfer of
routing the range of actions a user can perform on the network.
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