Controller - Institute of Transportation Engineers
Controller - Institute of Transportation Engineers
Controller - Institute of Transportation Engineers
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2. Modulation: Phase coherent frequency shift keying (FSK).<br />
3. Data Format: Asynchronous, serial by bit.<br />
4. Line & Signal Requirements: Type 3002 voice-grade, unconditioned Tone<br />
Carrier Frequencies (Transmit and Receive):2070-6A - 1.2 KHz MARK<br />
and 2.2 KHz SPACE, ±1% tolerance. 2070-6B - 11.2 KHz MARK and<br />
17.6 KHz SPACE, ±1% tolerance. The operating band shall be (half<br />
power, -3 dB) between 1.0 KHz & .4 KHz for 2070-6A and 9.9 KHz &<br />
18.9 KHz for 2070-6B.<br />
5. Transmitting Output Signal Level: 0, -2, -4, -6, and -8 dB (at 1.7 KHz for<br />
2070-6A & 14.7 KHz for 2070-6B) continuous or switch selectable.<br />
6. Receiver Input Sensitivity: 0 to -40 dB.<br />
7. Receiver Bandpass Filter: Shall meet the error rate requirement specified<br />
below and shall provide 20 dB/octave, minimum active attenuation for all<br />
frequencies outside the operating band.<br />
8. Clear-to-Send (CTS) Delay: 11 ±3 ms.<br />
9. Receive Line Signal Detect Time: 8 ±2 ms mark frequency.<br />
10. Receive Line Squelch: 6.5 (±1) ms, 0 ms (OUT).<br />
11. S<strong>of</strong>t Carrier Turn Off Time: 10 ±2 ms (0.9 KHz for 2070-6A and 7.8 KHz<br />
for 2070-6B). When the RTS is unasserted , the carrier shall turn <strong>of</strong>f or go<br />
to s<strong>of</strong>t carrier frequency.<br />
12. Modem Recovery Timer: Capable <strong>of</strong> receiving data within 22 ms after<br />
completion <strong>of</strong> transmission.<br />
13. Error Rate: Shall not exceed 1 bit in 100 Kbits, with a signal-to-noise ratio<br />
<strong>of</strong> 16 dB measured with flat-weight over a 300 to 3,000 Hz band.<br />
14. Transmit Noise: Less than -50 dB across 600-ohms resistive load within<br />
the frequency spectrum <strong>of</strong> 300 to 3,000 Hz at maximum output.<br />
15. Modem interface: EIA-232 Standards.<br />
5.1.4 Logic Switches<br />
Two LOGIC switches per circuit shall be provided (faceplate mounted).<br />
5.1.4.1<br />
One shall be used to vertically switch between Half-Duplex (Down) and Full-Duplex<br />
(Up). In Half-Duplex mode, the Transmit connections shall be used for both Receive and<br />
Transmit.<br />
5.1.4.2<br />
A MODEM Enable switch shall be provided that when in the UP Position shall enable<br />
MODEM and disable MODEM in the DOWN Position.<br />
5.1.5 Control Switch<br />
Standard for the ATC – Type 2070 March 29, 2001<br />
87
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