Meinberg TCR170PEX - Manual (Page 20)

20
Connectors and LEDs in the bracket
The bracket of the board includes the
BNC-connectors for the amplitude
modulated time codes (input/output),
two LEDs, a key for activating the
Bootstrap-Loader and a 9 pin D-Sub-
plug.
The LEDs signal the status of the
IRIG receiver. The right, bicolor LED
is switched to red whenever the inter-
nal timing of TCR170PEX is in holdo-
ver mode. This state arises after power
up and if an error in the IRIG telegram
is detected. This LED changes state
only at change of minute. This LED is
switched to green (lock) if the internal
timing of TCR170PEX is synchronized
to the received IRIG code by a PLL
(Phase Locked Loop). If the left, green
LED (code) is switched on, the IRIG
receiver detected a correct telegram at
its input.
Pressing the hidden key BSL is re-
quired for activating the Bootstrap-
Loader before updating the firmware.
The 9 pin D-Sub-connector is wired to the board’s serial port. Pin assignment can
be seen from the figure above. This port can not be used as serial port for the
computer. Instead, the clock uses the port to send out Meinberg's standard time string
in order to control an external display or some other external device. The string is
sent out once per second, once per minute or if requested by an incoming ASCII ‘?’.
It is also possible to change the board’s board time by sending such a string towards
the clock. Transmission speed, framing and mode of operation can be modified using
the monitor software. The string format is described in the section ‘Technical
Specifications’ at the end of this manual.
modulated
timecode input
modulated
timecode output
code lock/holdover
BSL key
RxD
TxD
GND