
Glossary
202
ISI
Inter Symbol Interference. Interference of information symbols caused by distortions
at the channel.
ISR
Information Receiving Station. The current information receiver.
ISS
Information Sending Station. The current information transceiver.
NRZ
Non Return to Zero.
NRZI
Non Return to Zero Inverse.
Prompt
The input request. The prompt indicates the readiness of the system to receive
commands. The PTC-IIIusb indicates e.g. the readiness with
cmd:
. TNCs using
TheFirmware
will display only an asterisk * as a prompt. Using DOS for example
the prompt looks like:
C:\DOS>.
PSK
Phase Shift Keying
RAM
Random Access memory
RMNC
The short expression for Rhein-Main-Network-Controller. A special hardware
especially developed for the use as a digipeater.
ROM
Read Only Memory. In the
SCS
PTC-IIIusb a special form of the ROM is used, the
so called FLASH-memory.
RS232
Standard for the transmission of serial data. Defines the pin-out of the connectors and
the voltage levels.
RS232 level
The voltage level of a serial interface in accordance with RS232 standard is defined as
follows: -3 to –15 V for a logical 1, and +3 to +15 V for a logical 0. The range
between –3 V and +3 V is not defined.
RTTY
R
adio
T
ele
TY
pe.
Rx
Receive. Short name for receive.
RxD