EMC Connectrix B Series Hardware Reference Manual page 124

Glossary
P
Packet A set of information transmitted across a network. See also Frame.
PAL Programmable Array Logic. A relatively small FPD.
Parallel The simultaneous transmission of data bits over multiple lines.
Participating Mode A mode in which an L_Port in a loop has a valid AL_PA and can
arbitrate, send frames, and retransmit received transmissions. See
also L_Port and Nonparticipating Mode.
Passive Copper A low-cost copper Fibre Channel connection allowing distances up to
13 meters between devices.
Path Selection The selection of a transmission path through the fabric. EMC
switches use the FSPF protocol.
Payload A Fibre Channel frame has a header and a payload. The payload
contains the information being transported by the frame; it is
determined by the higher-level service or FC_4 upper-level protocol.
There are many different payload formats.
PBC
Port bypass circuit. A circuit in hubs or a disk enclosure to open or
close a loop to add or remove nodes.
PCBA Printed circuit board assembly.
PCM Pulse-code modulation. A standard method of encoding analog
audio signals in digital form.
Performance A switch feature that monitors port traffic and includes frame
Monitoroing counters, SCSI read monitors, SCSI write Monitors, and other types
of monitors.
Persistent Error Log
Error messages of a high enough level (by default, Panic or Critical)
are saved to flash memory on the switch instead of to RAM. These
messages are saved over reboots and power cycles, constituting the
persistent error log.
Phantom Address An AL_PA value that is assigned to a device that is not physically in
the loop. Also known as phantom AL_PA.
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Connectrix B Series XPath OS AP-7420B Hardware Reference Manual