Ricoh FACSIMILE FAX77 Field Service Manual page 197

PSTN
Public Switched Telephone Network: The net-
work normally used for telephoning.
PSU
Power Supply Unit: The PCB that supplies
voltages to machine components.
QAM
Quadrature Amplitude Modulation: The
modulation technique which enables fax
machines to transmit at 9600 and 7200 bps
over the PSTN.
RTI
Remote Terminal Identification: The RTI is dis-
played on the other terminal's display panel
to identify the local terminal during com-
munication.
RTN
Retrain Negative: A protocol signal that in-
forms the transmitter that the previous page
was not received satisfactorily due to exces-
sive errors.
RTP
Retrain Positive: A protocol signal that in-
forms the transmitter that the previous page
was OK but modem retraining must be done
before continuing; this is normally because of
poor line condition.
SAF
Store And Forward: A memory used to hold
documents for transmission later or for broad-
casting, to receive confidential messages,
and to receive messages when the printer is
jammed or out of paper.
SBU
Scanner Board Unit: This PCB contains the
CCD.
SRAM
Static Random Access Memory: This PCB
contains the RAM which holds system
parameters such as bit switches, Quick Dial,
and NCU parameters.
TCR
Transaction Confirmation Report: The TCR
shows the date, time, RTI, mode, number of
pages, result, department code, file number,
and number of communications made by the
machine.
TTl
Transmit Terminal Identification: The TTl of
the sender is printed at the top of each page
as it is received at the other end. It identifies
the sender.
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