HM Electronics RFM100 Users Manual

AVDB

DRAFT

Advanced Vehicle Detector Board

Installation Instructions

HME# 400G767
Rev 9 8/15/17

DRAFT

TABLE OF CONTENTS

DRAFT

AVDB Theory of Operation..................................................................... 1

Loop Failure and Interference .................................................................. 1

Installation .................................................................................. 2

Regulatory Label Placement ................................................................... 3

Dip Switch Settings........................................................................... 4

Troubleshooting ............................................................................. 5

Reset Procedure ............................................................................. 5

Detector Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Self Diagnostics ............................................................................. 6

Regulatory Compliance Approvals .............................................................. 7

AVDB THEORY OF OPERATION

DRAFT

The AVDB uses digital signal processing techniques to assess parameters inherent to inductive ground loops in order to evaluate

loop status and signal vehicle detection. As a loop operator, this technology affords you the benet of understanding the quality of

your loop in real-time with advanced foresight and warning of deteriorating conditions.

This allows preventative measures to be taken to avoid down time and situations in which your drive-thru technologies and
services are hindered or incapacitated due to a failed or failing loop. While these events are unlikely, the advanced warning
system of the AVDB offers peace of mind that drive-thru operations will continue to be uninterrupted.

Through continuous measurement of the inductive ground loop, the AVDB determines the inherent electrical characteristics of
the loop which include: loop condition, connection quality, and the inductance of the loop. These three parameters are evaluated
to determine the Loop Status as seen in Figure 4, page 6. In the case of a deteriorating loop, the AVDB offers insight into the
underlying cause and the course of action to help troubleshoot your issue.

The vehicle detection portion of the AVDB operates through analysis of loop response to a stimulus provided by the detector,
which characterizes the inductance of a loop. The presence of a vehicle over the loop electromagnetically interacts with the loop
causing a change in inductance. The AVDB monitors these small inductance changes in order to signal vehicle detection.

LOOP FAILURE AND INTERFERENCE

Inductive ground loops may eventually fail. The AVDB can remove the surprise of failure from operation and allows you to prepare
for such an event well in advance. Loop failure is the result of damage to the loop which can include, but is not limited to: damage
to area surrounding loop, severed loop or lead in wires, or insulation damage as a result of aging and other environmental factors.

In addition, deteriorating connections between the loop and the AVDB can cause detection failure even though the loop itself is in
good condition.

The AVDB is essentially a large metal detector. Do not install the loop over any metallic object, surface, or area. This includes
installing the loop over rebar. Failure to adhere to this installation recommendation will result in unexpected loop behavior.

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