John, In RS-232 terms:
Assert = Positive Voltage = logic 0 Clear = Negative Voltage = logic 1 The only reason I mention the logic 0 & 1 is because in TTL terms it's backwards. A logic 0 for a TTL signal is 0 volts, and a logic 1 is ~5 volts. Many GPS devices that have a PPS output at TTL voltage levels (0 - 5v) but are RS232 biased. So if you tried to stick like a MAX232 chip on there to bring the voltages into the full RS232 voltage levels it would end up being upside down. You would need a voltage inverter to flip it back. It's best just to leave it as-is if the GPS device says they are already RS-232 biased. Back to your question though... flag2 0 = Voltage goes from low to high at the timemark (default) flag2 1 = Voltage goes from high to low at the timemark _______________________________________________ questions mailing list [email protected] https://lists.ntp.isc.org/mailman/listinfo/questions
