Regulated 5 V Input; Electrical Domains; Onboard Memory Logging; Gnss Antennas - Advanced Navigation Certus OEM Reference Manual

Certus Reference Manual • Installing Certus OEM
indicated in 5.3 Hardware
observe the + and – polarity indicated on the PCBA.
Take care when using a supply voltage close to the under-voltage lockout of 9.1 V, as small voltage changes
could engage the under-voltage shutdown and potentially oscillate between the on and off state unexpectedly. It
is recommended that the unit is always run at 9.5 V or higher.

6.4.2 Regulated 5 V Input

The 5 V input is only rated for inputs from 4.95 V to 5.05 V, exceeding 5.5 V can cause permanent damage to the
unit. The 5 V supply must be low noise (< 20 mV peak-to-peak).

6.5 Electrical Domains

Certus OEM ground planes are interconnected, and not electrically isolated across each domain.

6.6 Onboard Memory Logging

Certus OEM features an onboard high capacity memory for operation and data logging. The memory card is not
a user serviceable part, and should not be removed or modified as it is used during normal operation of the unit.

6.7 GNSS Antennas

Note: The following is written with respect to Certus D and dual antenna applications. However, a lot of
information is still relevant to single antenna applications and Certus N.
GNSS antennas should be installed level with respect to each other, with a clear unobstructed view of the sky,
away from reflective surfaces and with the shortest cable run to the Certus unit permitted by the application. The
antennas should be mounted away from any RF emitters such as radars, high-powered communication links,
etc. It is important to have a ground plane (flat conductive surface such as a piece of plate aluminium) under the
antenna with a minimum radius of 60 mm or as recommended by the antenna supplier. Correct antenna
positioning is critical for Certus's dual-antenna heading function.
The primary GNSS antenna position offset should be configured in the Certus unit by using the Alignment page
in the web UI or Certus Manager. See
antenna offset is measured from the physical centre of the Certus unit to the central base (ARP) of the primary
GNSS antenna in the body co-ordinate frame (X+ forward, Z+ down).
Note: The Z axis is positive downwards, mounting the antenna above the Certus unit will require a
negative Z offset. It is very important to set this antenna offset accurately as Certus corrects for lever
arm velocities. An incorrect GNSS antenna offset will lead to performance degradation under turning
and angular rotations.
An example installation with the body co-ordinate frame axes marked is shown below in Certus antenna offset
isometric view and Certus antenna offset front view. In this installation below with an antenna mounted on the
right-hand side of the vehicle roof, further forward from the Certus unit, there would be a positive X antenna
offset value, a positive Y antenna offset value and a negative Z offset value.
v2.4
Specifications. For the avoidance of doubt, if wiring your own JST connector,
8.1 Using the Web User Interface
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or 8.2 Using Certus Manager. The
2024-12-17