Meinberg DCF77 PCI510, Operating Instructions Manual, Page: 10 / 22

10
Overview
Because the radio clock PCI510 is designed as an universal board for computers with
PCI bus, operation within 3.3V and 5V systems is possible.
An external ferrit antenna makes the signal from DCF77 available to the on-board
long wave receiver. The demodulated time marks are decoded by the clock´s micropro-
cessor. If no errors are detected in the current time message an additional plausibility
check against the previous time message is performed. If that plausibility check passes,
too, the buffered real time clock on the board is synchronized corresponding to the
decoded time and date. Optionally, the decoded date and time information can be
converted to another time zone. The time zone setting can be modified using the
monitor program. The current setting is saved permanently on the radio clock board.
Software running on the computer can read out the date/time/status and some more
information. Access to the board is made via writing to/reading from I/O ports. It is
possible but not necessary to let the board generate periodic hardware interrupts on the
computer bus.
The diskette contains a driver program that keeps the computer´s system time
synchronous to the board time. If the present delivered diskette doesn’t contain a driver
program for the operating system used, it can be downloaded from:
http://www.meinberg.de/english/sw/
Pulse outputs
The radio clock PCI510 generates pulses whenever a new second (P_SEC) or a new
minute (P_MIN) begins. The P_SEC pulse is available with TTL level (0/+5V) and
RS-232 level (-3..12V/+3..12V), the P_MIN signal with TTL level only. If required,
DIL switches can be set up to direct each of the pulses to a corresponding pin of the 9
pin connector in the rear panel.