User's Manual

12 Versus Technology, Inc.
A single sensor placed near the middle of the ceiling can usually effectively cover an office or meeting
room. Offices or rooms as large as 30 feet square are generally covered by a single sensor. The sensor
should be located so that it has the best possible view of the room. If the room is very large or has a
complex shape and no single sensor position will provide adequate coverage, multiple sensors will be
needed.
3.3.2.3 Overlapping Sensors
Sensor overlap occurs when two (or more) sensors are placed so that their fields of view overlap. This
will cause some indecision in the system if both sensors see a badge at the same time. The software
will not change the location of a badge when it is in an overlap area unless the option to send duplicate
hits is selected in the Badge Server software. If the option is selected, a badge may appear to bounce
back and forth as long as it is in an overlap condition. This increases the traffic on the system and it is
not recommended that the option be selected.
3.3.2.4 Sunlight interference
If the room has windows that allow a large amount of sunlight to enter the room, place the sensor in a
position where the sunlight does not reflect directly into it from objects in the room. Sunlight can
decrease sensor range and field of view if allowed to enter the sensor. Window tint films that block
infrared (heat) energy greatly reduce this effect.
3.3.2.5 IR Sensor interference from nearby lighting or other electrical fixtures that
may emit EMI noise
System performance can be adversely affected by;
1. Light that is aimed directly into the sensor.
2. EMI noise emitted by nearby electrical fixtures.
Symptoms of sensor interference are:
1. A voltage drop below 15.5 volts.
2. Badges that are not picked up by the sensor or only picked up intermittently.
Do not mount sensors near lights or electrical fixtures unless absolutely necessary. If the performance
of an IR sensor is in question, move the sensor as far away from any nearby lights or electrical fixtures
as is practical.
To avoid problems with light interference:
If sensors must be mounted near lights;
1. Mount sensor as far from the light as possible
2. Mount sensor so that the light does not have a direct path into the sensor “eyes”.
3. As a last resort, mask the eyes of the sensor that are receiving the direct light, using electrical
tape. (Caution: this disables the sensor operation in that direction).
To avoid problems with EMI noise:
1. Do not mount IR sensors near suspect fixtures.
2. Do not run sensor connection cables near suspect fixtures.
3.3.3 RF Sensor Location Planning
Planning the location of RF sensors depends upon the facility. In most cases, for complete coverage,
they can be placed approximately 100’ apart, because they have a sensitivity range radius of 50’.
However, because concrete and steel structures absorb the RF signal, and other materials affect the
strength of RF signals, testing is necessary to determine the best placement of RF sensors. In multi-
floor facilities, it is desirable to stagger locations, i.e. do not place the one on the third floor directly
above the one on the second floor, for better coverage.