Special Configurations - ABB Excount II User Manual

4. Using the transceiver

4.9 Special configurations

If the sensor is located a significant height above the ground, it may be dif-
ficult to make contact since it is not practical to be within the contact zone
as described in section 4.8. Examples are tall transmission line towers and
gantries. The taller the structure, the smaller the contact zone at ground level.
For these special configurations, a separate hand-held external antenna is
available as an option. This is a directed antenna which focuses the signal in
order to boost the effective strength and thereby increase the communication
distance. Since the signal is directed, the external antenna must be pointed
directly at the sensor's in-built antenna in order to obtain the optimum signal
strength.
Direct and completely unobstructed line-of-sight is preferable between the
transceiver antenna and the sensor during communication. The first attempt
for communication should always follow the guidelines given in section 4.8,
but with the external antenna pointed directly at the sensor. If difficulties are
experienced, trial different locations around the sensor. Note that different
contact zones may apply for each phase or individual readings (see section
4.10). If necessary, and is possible to do safely, it is recommended to finally
stand directly under the sensor while making measurements using the exter-
nal antenna in such special configurations. See figure 4.9.1.
Use of the external antenna may even assist communication in standard
configurations which otherwise have difficulty making contact because of
external factors.
40
Use of hand-held external antenna in special configurations
Figure 4.9.1
1HSA 801 080-15en EXCOUNT-II Users Manual