Radio Code Line
From Signal Identification Wiki
- Replaced pole-to-pole wiring along railroad between signal locations.
- Non-vital supervisory data link (R/Link by Safetran as example)
- FSKFrequency-Shift Keying/FMFrequency Modulation at 160 MHZ, UHFUltra High Frequency (300-3000 MHz), or 900 MHzMegaHertz (MHz) 10^6 Hz.
- Transmitted code system control messages and indication messages via RFRadio Frequency carrier between office and field location (wayside).
- Operated from 300 baudBaud (unit symbol Bd) is the unit for symbol rate or modulation rate in symbols per second. to 4800 baudBaud (unit symbol Bd) is the unit for symbol rate or modulation rate in symbols per second.
- Vital data was carried in coded AF track circuits.
- Later versions (HD/Link by Safetran) used ATCS-200 messaging protocol to send vital data between field locations by radio. HD/Link radio was spread-spectrum low power.
- Also used to relay AEI data and wayside detector data to signal locations.