Specifications

78 Telephonics
Tone Levels
The DTMF tones must typically be at least 12 dB louder than the noise
floor and 16 dB louder than any other tone within the DTMF detection
band. Each frequency of the DTMF tone must be between -5 dBm and -26
dBm when measured at the DECvoice telephone line connections.
B.6 Wink Detection
DECvoice can detect momentary losses in loop current. DECvoice can
use these losses to detect that the other end of the telephone call has
cleared down. The wink detector must see a current absence of 30 ms
or more. DECvoice detects the trailing edge of the current loss. In
other words, DECvoice detects the reestablishment of loop current. Not
all telephone systems generate winks to signal call disconnect. Some
telephone systems may generate winks at other times (the call waiting
beep is often accompanied by one or more winks).
B.7 DTMF Dialing
DECvoice can generate outgoing calls using DTMF tone dialing. DTMF
dialing uses the standard DTMF frequencies (see the Tone Frequencies
section). There is a 0.1% maximum frequency error. Country-specific
regulations determine the timing and power.
B.8 Pulse Dialing
DECvoice can generate outgoing calls using pulse (rotary) dialing. The
digits are pulse dialed at a rate of 10 pulses/s. The average make interval
is 40 ms. The average break interval is 60 ms. The interdigit interval
is 0.8 seconds. These characteristics may change as country-specific
regulations require.