Meinberg GPS167TGP, Operating Instructions Manual

Page: 11 / 62

11
Time Capture Inputs
Two time capture inputs called User Capture 0 and 1 are provided at the rear connector
(CAP0 and CAP1) to measure asynchronous time events. A falling TTL slope at one
of these inputs lets the microprocessor save the current real time in its capture buffer.
From the buffer, capture events are transmitted via COM0 or COM1 and displayed on
LCD. The capture buffer can hold more than 500 events, so either a burst of events
with intervals down to less than 1.5 msec can be recorded or a continuous stream of
events at a lower rate depending on the transmission speed of COM0 or COM1 can be
measured. The format of the output string is ASCII, see the technical specifications at
the end of this document for details. If the capture buffer is full a message "** capture
buffer full" is transmitted, if the interval between two captures is too short the warning
"** capture overrun" is being sent.
Asynchronous Serial Ports
(optional 4x COM)
Four asynchronous serial RS232 interfaces (COM0 ... COM3) are available to the
user. In the default mode of operation, the serial outputs are disabled until the receiver
has synchronized after power-up. However, the system can be configured to enable
those outputs immediately after power-up. Transmission speeds, framings and mode
of operation can be configured separately using the setup menu. COM0 is compatible
with other radio remote clocks made by Meinberg. It sends the time string either once
per second, once per minute or on request with ASCII ´?´ only. Also the interfaces can
be configured to transmit capture data either automatically when available or on
request. The format of the output strings is ASCII, see the technical specifications at
the end of this document for details. A separate document with programming instruc-
tions can be requested defining a binary data format which can be used to exchange
parameters with GPS167 via COM0.