Advent Instruments Inc.
Glossary of Terms
Glossary of Terms
ACK Tone
Acknowledgement signal sent by the TE in response to detecting a DT-AS or CAS tone.
The signal is usually a DTMF digit 'D' or 'A'.
Bell 202
An FSK modulation standard that uses 1200 Hz for the mark tone frequency and 2200 Hz
for the space tone frequency. The baud rate used is 1200 bits per second.
CAS Tone
CPE Alerting Signal. See DT-AS.
Channel Seizure
A FSK modulated alternating zero/one bit pattern that may be sent prior to any data
bytes.
Checksum
For the purposes of Caller ID or SMS DLL, the checksum is a byte value sent after the
message data. It represents the two's complement sum of all the message byte values.
Used for error detection.
dBm
Unit of signal power level. Calculated as 10 times the base 10 logarithm of the ratio of
the signals power relative to 0.001 Watt. For example, 1 mW = 0 dBm, 100 mW = 20
dBm. For most telephone applications, signal levels expressed in dBm are expressed
with a 600 ohm terminating impedance. This fixes the relationship between dBm and
dBV as 0 dBm = -2.218 dBV, or 0 dBV = 2.218 dBm.
dBV
Unit of signal voltage level. Calculated as 20 times the base 10 logarithm of the signal's
voltage. For example, 1 Vrms = 0 dBV, 0.1 Vrms = -20 dBV.
AI-7280 Programmers Guide - Direct Control
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