Intermec Janus 2050 User Manual page 399

JANUS 2050 Vehicle-Mount Computer User's Manual (4MB)
PCMCIA
Personal Computer Memory Card International Association. This group of
manufacturers has defined a set of hardware and software standards for
memory and expansion PC cards that are available for personal computers.
PC Standard communications protocol
A communications protocol that handles data transfer on a character-by-
character basis or by either filling a receive buffer or transmitting a buffer of
data. This protocol is designed to be compatible with the standard PC BIOS
functions. The one exception is that the PC Standard protocol can buffer data
that is received to avoid losing characters if a program has not checked for data
recently.
physical RAM drive
See RAM drive.
Plessey Code
A fixed length, continuous, and not self-checking bar code symbology. Plessey
code is pulse-width modulated. It includes a start character, data characters, an
eight-bit cyclic check digit, a termination bar, and usually a reverse start
character.
Point-to-Point protocol
Point-to-Point is an unsolicited protocol in which the device transmits data
whenever it has something to transmit. The data is followed by a CR LF as the
EOM characters. The device is always in a receiving state and does not wait for
select commands. This protocol does not perform any error checking or
acknowledgment handshaking. Point-to-Point protocol is typically used to
connect the device to a CRT terminal or host computer.
POL
Poll character. Sent by the host to request device data. For User-Defined Multi-
Drop protocol, you must define a unique character for each device on a data
line.
Polling Mode D
Polling Mode D is a communications protocol that requires the host computer
to ask the device for data it might have (polling) and to request to send data to
the device (selecting). Polling Mode D is used to connect multiple devices to a
single multiport controller. PC-IRL uses this protocol.
POST
Power-on self test. This test runs when you warm or cold boot the device. The
test ensures that the hardware and peripherals are operational.
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