Practical_modern_SCADA_protocols_-_dnp3,_60870-5_and_Related_Systems

408 Practical Modern SCADA Protocols: DNP3, 60870.5 and Related Systems
Port
Presentation layer
Protocol
PM
PSDN
PSTN
PSK
PTT
PVC
(1) A place of access to a device or network, used for input/
output of digital and analog signals. (2) A number used by the
transmission control protocol to identify individual processes
(programs) running on a computer.
Layer 6 of the ISO/OSI Reference Model, concerned with
negotiation of a suitable transfer syntax for use during an
application, for example the translation of EBCDIC to ASCII.
Encryption is also handled at this level.
A formal set of conventions governing the formatting, control
procedures and relative timing of message exchange between
two communicating systems.
Phase Modulation.
Public Switched Data Network. Any switching data
communications system, such as Telex and public telephone
networks, which provides circuit switching to many customers.
Public Switched Telephone Network. This is the term used to
describe the (analog) public telephone network.
Phase Shift Keying a.k.a. Binary Phase Shift Keying (BPSK).
Post, Telephone and Telecommunications Authority.
(1) Polyvinyl chloride. (2) Permanent Virtual Circuit.
QAM
QoS
Quadrature Amplitude Modulation.
Quality of Service.
R/W
RAM
RAS
Reactance
Repeater
Resistance
Response time
RF
Read/Write.
Random Access Memory. Semiconductor read/write volatile
memory. Data is lost if the power is turned off.
(1) Remote Access Server. (2) H.323 Registration, Admission
and Status.
The opposition offered to the flow of alternating current by
inductance or capacitance of a component or circuit.
An amplifier which regenerates the signal and thus expands the
network.
The ratio of voltage to electrical current for a given circuit
measured in ohms.
The elapsed time between the generation of the last character
of a message at a terminal and the receipt of the first character
of the reply. It includes terminal delay and network delay.
Radio Frequency.