Installation manual

APPENDIX 6
Glossary of Terms (continued)
Digital PSTN Digital Public Switched Telephone Network.
The digital national telephone system. Service is available to customers on
twisted-pair wires that carries a DC supply provided from the network tel-
ephone exchange, on optical fibre or other digital transmission medium. The
digital service may be in ISDN format or another digital format.
DTMF Dual Tone Multi Frequency
The series of tones used by telephones to send dialling information to an
analogue PSTN exchange. These tones are also used by the DTMF Fast
Format and Contact ID alarms reporting protocols.
DTMF Fast Format Alarms Reporting Protocol
A protocol that is a sequence of analogue tones (push-button telephone
tones) used to send via telephone lines a transmission to receiving equip-
ment at an ARC, and to receive checking and acknowledgement replies
from that receiving equipment. 8 or 16 channel DTMF Fast Format protocol
is commonly used in burglar or intruder alarm equipment.
Earth Loop Calling
An older type of analogue PSTN or analogue PABX extention line. Normally
provided with no DC voltage present on the line. Requires the line to be
connected to earth to obtain a ‘dial tone’. CSL Dualcom, Digicom and Con-
trol Panel Digi-Modems can not be used with this type of telephone line.
EEPROM Electrically Erasable Programmable Read Only Memory.
A type of NVM. See NVM
FSSI Forward Signal Strength Indication
This is a value indicating the radio signal strength recieved at a Dualcom.or
VDN radio PAD from the base station.
Hybrid Line
A line that carries digital data and analogue signals simultaneously. Most
commonly this is an ADSL digital service and an analogue telephone serv-
ice on one line from a Service Provider to a subscriber.
ISDN Integrated Services Digital Network
A digital communication network where services are provided via electrical
or optical cables. This may also be a digital PSTN. The network is usually
provided as a 2 channel or 30 channel ISDN service.
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