- 77.5 kHz carrier frequency
- Second marks to modulate the carrier’s amplitude
- PRN sequence and PRN window to modulate the carrier’s phase
- Pulse-per-Second (PPS) output
Additionally, an IRIG or AFNOR time code signal is generated, and a serial time string can be transmitted which includes the generated absolute date and time.
All signals are derived from a single 10 MHz reference frequency. That frequency can either be generated by a high quality on-board oscillator, or it can be supplied externally. The frequency source is selected by a jumper on the printed circuit board. The leading edge of the second marks can be synchronized by an external PPS input signal.
Internal date and time is always based on UTC. A configurable time offset can be applied to the UTC time base to compute a local standard time. Beginning and end of a period of daylight saving time can either be computed year by year based on a simple, configurable algorithm, or can be configured for the current year. GEN170 generates the proper changeover announcement flags as required by the DCF77 coding scheme.
Additionally, a date for insertion of a leap second can be configured. Actually, leap seconds are only inserted at UTC midnight. GEN170 automatically generates the coding sequences to announce the leap second as required for DCF77 and NTP, and also inserts the leap second correctly.