Sur-Gard SG-System III, Руководство по эксплуатации

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CHAPTER FIVE - ADVANCED PROGRAMMING
86
SG-Sys
tem I Operating Man
ual
5
SG-DRL3 Option B9: Noise/Fax Detection
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SG-DRL3-2L Option 1B9/2B9: Noise/Fax Detection
Default (00)
This option will allow the receiver to perform line condition tests when the call is answered. There are two functions that are performed
when a call is received: Noise Detection, and Fax Detection.
To enable Noise/Fax and Fax Tone detection set the following:
Noise/Fax Detection
This will occur during pre-init handshake duration (see Option 05/105/205) to perform the Fax/Noise test on the line. The DSP will require
at least 150ms to evaluate the line and determine if it is noisy or a fax transmission is occurring. Overall, one cycle of this will require at least
250ms duration. If the pre-init handshake has not expired, the line card will perform the test again if it did not detect a Fax or Noise report. If
a fax or Noise report was detected the receiver will generate a communication fail fax or a communication fail noise message.
If Noise is detected the receiver will continue to proceed through its programmed handshakes and format detection. If no valid signal is
received then the receiver will log the call as a Communication Fail - Noise detected. If a valid signal is received (for example a SIA event)
the signal will be processed as normal and no fail log will be made.
Fax tone detection
This will occur in the common mode detection for formats. In this check, the line card is looking for the 1170 ON report from the DSP. Once
in this check, the line starts a 600 ms timer to check for the 1170 OFF report. If it sees the OFF report a valid fax tone is detected. If the line
card does not detect any other formats after the last handshake, it will generate a communication fail fax message. To avoid conflicting with
other formats the sync bit for SIA is checked. However, there is no way at the moment to distinguish from the modem II formats. At most the
receiver will miss the first bytes of modem, but once it detects modem, the second round is properly received.
There are four types of Communication Fail messages that can be created:
•A message is generated if the line card receives an Invalid DNIS.
1 13 digits DTMF format Scantronics 4-8-1, Ademco Highspeed 4
2 8 digits DTMF format Sur-Gard 4-3 with checksum, 4-3-1 FBI Superfast, Ademco 4-1 express
3 22 digits DTMF format Contact ID 10 digit
4 11 digits DTMF format Acron 3, Ademco Highspeed 2, Scantronics 2-8-1
5 12 digits DTMF format Acron 4, Ademco Highspeed 3, Scantronics 3-8-1
6 23 digits DTMF format Scantronics 6-16-1
7 14 digits DTMF format Scantronics 4-8-1 with checksum, Scantronics 5-8-1
Option bit value Setting
0000 0000 No noise or fax and tone detection
0000 0001 Noise/fax detection enabled
0000 0010 Fax tone detection enabled
0000 0011 Fax /noise and tone detection enabled
Bit Description Example Formats