Motorola M12 Oncore User's Guide download pdf (Page 29)

Chapter 3 – Receiver Description

Motorola GPS Products - Oncore User’s Guide

Mounting Hardware

(Continued)

Sturdiness and Reliability of Metal Standoffs

The Oncore PCB mounted on standoffs 0.375 or 0.500 in. long passed the vibration test

successfully. The mechanical test is conducted in three axes, one hour each, at 7.7

Gs random vibration. In the final analysis this is a severe military specification as per

MILSTD 810E. After the vibration test leg of the design validation, the screws lose

about 60% to 80% torque, which is expected as per design. Also, all the parts

populated on both sides of the Oncore PCB remain soldered to the PCB with no loose

connections.

Motorola has also conducted independent vibration tests such as the SAE J1455

Truck Cab spec. (1.04 Gs for four hours per axis) and the SAE J1211 Car Chassis spec.

(2.57 Gs for four hours per axis). Both of them passed successfully with the GT

Oncore PCB mounted on 0.375 in. high standoffs.

Motorola conducted independent mechanical shock tests at the 30 G level (10 ms

duration) at least 100 times, which also passed successfully.

Design Worksheets

Given below in figures 3.9 and 3.10 are sample worksheets which show the Oncore

and the application PCB mounted in two different ways. The purpose of these

worksheets is to provide the reader with recommended design guidelines.

Figure 3.9: Sample layout of GPS Oncore PCB which is directly

connected to the application PCB

Revision 5.0 08/30/02

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Motorola M12 Oncore User's Guide Page 29