The DIP-switches should be set for 9600 bps line speed, 24-hour day-of-year format and UTC time zone. Automatic correction for DST should be disabled. It is very important that the year be set correctly in the DIP-switches; otherwise, the day of year will be incorrect after 28 April of a normal or leap year. The propagation delay DIP-switches should be set according to the distance from the transmitter for both WWV and WWVH, as described in the instructions. While the delay can be set only to within 11 ms, the fudge time1 parameter can be used for vernier corrections.
Using the poll sequence QTQDQM, the response timecode is in three sections totalling 50 ASCII printing characters, as concatenated by the driver, in the following format:
ahh:mm:ss.fffs<cr> yy/dd/mm/ddd<cr> frdzycchhSSFTttttuuxx<cr> on-time = first <cr> hh:mm:ss.fff = hours, minutes, seconds, milliseconds a = AM/PM indicator (' ' for 24-hour mode) yy = year (from DIPswitches) dd/mm/ddd = day of month, month, day of year s = daylight-saving indicator (' ' for 24-hour mode) f = frequency enable (O = all frequencies enabled) r = baud rate (3 = 1200, 6 = 9600) d = features indicator (@ = month/day display enabled) z = time zone (0 = UTC) y = year (5 = 91) cc = WWV propagation delay (52 = 22 ms) hh = WWVH propagation delay (81 = 33 ms) SS = status (80 or 82 = operating correctly) F = current receive frequency (4 = 15 MHz) T = transmitter (C = WWV, H = WWVH) tttt = time since last update (0000 = minutes) uu = flush character (03 = ^c) xx = 94 (unknown)The alarm condition is indicated by other than 8 at a, which occurs during initial synchronization and when received signal is lost for an extended period; unlock condition is indicated by other than 0000 in the tttt subfield.
Reference Clock Drivers