Applications
VOCORD A4 is used in multi-channel audio registration systems for recording signals from analog telephone lines, microphones, and other line outputs.
Description
VOCORD A4 features high quality line interface. At sample frequency of 8 kHz the signal/noise ratio amounts to 78 dB. Hardware audio compression considerably decreases central processor loading and allows to create multifunction and trusted audio-recording systems.
Using VOCORD A4 and the pertaining equipment produced by Vocord one can obtain a fax demodulator and decoder supporting the following fax protocols: Fax SuperG3, Т.30, Т.4, Т.6, V.21, V.8bis, V.27ter, V.29, V17, V34 (up to 33600 bps).
Technical Specifications
| Parameter | Value |
|---|---|
| Number of channels | 4 |
| Max number of boards in a system unit | 16 |
| Telephone interface | |
| Type of interface | Two-wire |
| Input resistance (at parallel connection) | 1 MOhm |
| Frequency range | 300-3500 Hz at 8 kHz; 300- 7000 Hz at 16 kHz; 300 - 13000 Hz at 32 kHz |
| Input connector | DB25 |
| Analog interface | |
| Sampling frequency | 8, 16, 32 kHz, quantization being 16 bit |
| Input signal preamplifier | Up to 22.5 dB (increase interval is 1.5 dB) |
| Signal/noise ratio | 78 dB |
| Harmonic factor | -75 dB |
| Intermodulation factor | -70 dB |
| Line voltage measurement | ±200 V accurate within 0.2 V, refresh rate is 200 Hz |
| Peak audio amplitude | Up to ±7V (amplitude) |
| Transmitting signal (speech, tones, CALLER ID) to line | Peak amplitude is +3 dB |
| Galvanic isolation | > 1000 V |
| In-phase rejection | 80 dB |
| Sound processing | |
| AGC range | Up to 18 dB (program preset) |
| Audio compression | G.711, GSM 6.10 |
| Additional functions | |
| Detection of calling signal | From 20 V in the range of 16.7 to 100 Hz |
| Electret microphone support | Supply 5 V, 1 kOhm, balanced input |
| Detector of modem and fax transmissions | V.21, V.8bis, Bell202, V.17, V34, V.90, V.92, T.30, V.27ter, V.29, V17. |
| Remote user number identification | CALLER ID |
| PC interface | |
| PCI-bus | PCI 2.2 BusMaster 32 bit, 32 MHz |
| Form factor | PCI half size (150х106 mm) |
| Power supply | |
| +5 VDC | < 300 mA |
| ±12 VDC | +12 В < 200 mA; -12 V 0 mA |
| Operation temperature | From 0°C to +50°C |
| Storage temperature | From -20°C to +70°C |
| Humidity | From 8% to 80% |
| System requirements | |
| Operating system | Windows 2000/XP/2003 |
| RAM | 128 MB for Windows 2000/XP/2003 |
