2 – Installation
DPN 402197 Issue 7.1
© Teledyne Limited
2- 21
2.3.5 Subsea Altimeter
CAUTION
If you do not use the Altimeter port on the SEP, you must fit the correct blanking
plug supplied with the system to protect it from contact with sea water.
If you do not fit this blanking plug, rapid corrosion of the port will occur and the port
will fail. Sea water will enter the SEP through the corroded port to cause total
failure of the SEP.
CAUTION
The 6-way SEP ports for connecting the altimeter and the attitude sensor are
identical. To avoid possible damage and to ensure correct operation, connect the
altimeter
only
to the ‘Altimeter’ port identified by a label on the SEP end cap. This
version of the 350 system does not use the ‘Sensor’ port and you must ensure
there is a correct blanking plug fitted to it during subsea operations.
2.3.5.1 Direct connection to the SEP
Use this method for the Teledyne TSS or Teledyne Benthos subsea altimeters. The SEP provides
power to drive these altimeters.
Route the cable from the altimeter to the SEP. Secure the cable at regular intervals along fixed frame
members of the ROV. Avoid introducing any sharp bends or other points of mechanical stress along
the cable.
Connect the cable to the ‘Altimeter’ port of the SEP. Tighten the knurled locking collar by hand only.
Do
not overtighten this connector
.
2.3.5.2 Connection to the topside computer
Use this method to connect all other types of altimeter compatible for use with the HydroPACT 350
system.
These altimeters use RS232 communications. To send their signals through the umbilical, you must
add them to the ROV multiplex unit and extract them at the surface. You must also provide a separate
power supply for the altimeter.
Generally, these types of altimeter have different data formats. Refer to
for details of these
formats.
Make the following provisions if you intend to use one of the compatible alternative altimeters with the
HydroPACT 350 system:
❐
Connect the altimeter to an available serial port. This will normally be the ‘COM2’ port. Note
that, because the altimeters use RS232 communications, they cannot transmit their signals
farther than approximately 15 metres. Therefore, you must add the altimeter signals to the
ROV multiplexer and then extract them at the surface. You must then convert the signals to
RS232 for application to the topside computer.
❐
Provide a separate power supply to drive the altimeter.