Meinberg GPS167PC, Руководство по эксплуатации

Страница: 9 / 28

9
Connectors and LEDs in the Rear Slot Cover
The coaxial antenna connector, two status LEDs and a 9 pin sub
D connector can be found in the rear slot cover. (see figure).
The upper, green LED (LOCK) is turned on when after power-
up the receiver has acquired at least four satellites and has
computed its position. In normal operation the receiver position
is updated continuously as long as at least four satellites can be
received.
The lower, red LED (FAIL) is turned on after power-up until
the receiver has synchronized or if a severe error occurs during
operation.
The 9 pin sub D connector is wired to the GPS167PC's serial
port COM0. Pin assignment can be seen from the figure beside.
This port can
not be used as serial port for the computer.
Instead, it can be uses to send out Meinberg's standard time
string to an external device. A DIL switch on the board can be
used to wire some TTL inputs or outputs (0..5V) to some
connector pins.
In this case, absolute care must be taken if
another device is connected to the port, because voltage
levels of -12V t12V (as commonly used with RS-
232 ports) at TTL inputs or outputs may damage the radio
clock.
Behind the little hole in the slot cover there is a push button
which is needed if the clock's firmware shall be updated. See the
chapture about firmware updates for details.
Installing the Radio Clock
Before the clock can be installed in the computer, some configuration may be required
if the desired settings differ from the default settings.
Setting The Port Base Address
Programs can read data from or write data to the board using 2 I/O ports from a block
of four addresses. The base I/O address can be set up in a wide range using the DIL
switch on the board. When being shipped, the board´s address is set to 300h corre-
sponding to the default address used by the utility software. If one of the levers 8, 9, or