BEWATOR COTAG 4101-2, Installation Handbook, Page: 141 / 158

Fault finding
19-9
Large quantities of noise
It is possible that very large quantities of interfering electrical noise
from a piece of equipment such as a computer monitor, very close to
the reading head, could reduce its receive range. If there is noise, the
amber LED will light continuously or flash.
Solution : move the interfering device a short distance from the
reading head. Reading heads have high noise immunity so you
shouldn’t need to move the noise source very far for full range to
return.
Low receive range with a loop antenna
(The 922 Test Card shows the correct Tx range but its LED does not
pulse showing that it is being read until it is close to the antenna.)
Noise
When using loop antennas the most common reason for reduced
range is interference by electrical noise. You should always use an
IAM to check a location before installing a loop and use a reading
head instead if there is likely to be a noise problem. The surrounding
environment can still change, however, resulting in new noise sources
being introduced. Some loop configurations are more resistant to
noise interference than others - see the chapter on “Antennas” for
more information.
Solutions : locate the source of the noise using an IAM. When you
have found the noise source, turn it off to verify that it is the cause of
the problem.
•
The best solution to a noise problem is to remove the source of
the noise, or suppress it.
•
If this is not possible, try linking in the attenuator circuit in
the Loop Coupler (see the chapter on “Antennas”).
•
If that doesn’t work, you can attempt noise cancelling using
discrete receive antennas (described in the same chapter).
Bad connections
There may be a wiring fault.
Solution : check the connections.
Threshold potentiometer on RF module has been moved
This potentiometer is factory set and marked.