PROM
Programmable Read Only Memory.
Propagation Delay
The time required for a signal to travel from one end of a circuit to another.
Protocol
A set of conventions controlling the timing and format of data communications between two pieces of communications equipment.
Protocol Convertor
Device that converts from one protocol to another.
Public Domain Software
Software from which its author has relinquished copyrights. This software is free of charge and may be distributed for
Public Switched Network
Telephone system providing circuit switching to many customers.
Pulse
An abrupt and relatively short change in voltage, either positive or negative, resulting in the conveyance of data in a circuit.
Q
Quadrature Amplitude Modulation (QAM)
A modulation technique which employs both amplitude and phase modulation to encode multiple bits in a single element.
R
RAM
Random Access Memory.
Received Line Signal Detector
See Carrier Detect.
Redundancy Check
Technique of error detection involving the transmission of additional data related to the message so that the receiving device can determine if the data transmitted is valid
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