Table of Contents
Advertisement
GPT description and maintenance
Ethernet TP Connector. The newer Twisted Pair interface is
also provided; IEEE 802.3 compliant 10 Mbit/s Ethernet. This
interface includes differential signals for transmit and receive.
Auxiliary Connector. The I/O board contains a 25-pin female
Delta connector handling various external interface signals. An
analogue heave sensor can be connected to pins 3 and 16, 1 and
14 is for pitch and 2 and 15 is for roll. One differential input is
connected to the sensor output terminal, and the other input is
grounded at the sensor in order to prevent ground potential
offsets between the sensor and the transceiver from adding to
the sensed signal. The differential input range is ±10 V.
Fixed input scaling factor for heave is 1 V/m. For roll and pitch
it is possible to select 1 V/degree or Volt = 10 sin(angle).
Some transducers contain a built-in thermistor (temperature
sensitive resistor, 10 kohm at 25°C) for measuring the water
temperature. The thermistor wires are connected to pins 4 and
17.
Pins 5, 6, 7 and 8 contain supply voltages sufficient for small
external adapter and conversion modules.
TrigIn and TrigOut are digital signals provided for transmit
synchronisation with external equipment of various makes. The
two TrigOut signals are open collector outputs (max 100 mA)
containing a 100 kohm pull-up resistor to +5 V. TrigOut+ is
normally low (output transistor is conducting), and TrigOut- is
the logical inverse of TrigOut+.
In internal trigger mode the sounder starts transmitting as soon
as it is ready for the next ping. TrigOut+ goes high (output
transistor is not conducting) when the transmit pulse starts, and
it goes low again when all frequency channels within the
transceiver have finished transmitting. The TrigIn signals are
totally disregarded. In external trigger mode the behaviour of
these signals is slightly different. Transmission is delayed until a
pulse is detected at one of the TrigIn inputs; a low-to-high
transition at the TrigIn+ input or a high-to-low transition at the
TrigIn- input. TrigOut+ goes high when the transceiver is ready
to transmit, and it goes low again when all frequency channels
within the transceiver have finished transmitting.
The RemoteIn signal at pin 23 switches the transceiver on/off.
Left open the transceiver is on. If grounded (< +2.5 V) the
transceiver is off.
63
857-164688 / E
Advertisement
Table of Contents
