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7.7.11 Aligning the PTP 600 Series Bridge ODUs
The following is a description of the steps taken to establish a radio link between the two
units forming the bridge and align the units for the best signal strength.
The PTP 600 Series Bridge uses audible tones during installation to assist the installer with
alignment. The installer should adjust the alignment of the ODU in both azimuth and elevation
until highest pitch tone is achieved12. The tones and their meanings are as follows:
State Name Tone
Description State Description Pitch Indication (Higher
pitch = higher power)
Free Channel
Search Regular beep Executing band scan N/A
Scanning Slow broken
tone Not demodulating the wanted
signal Rx Power
Synchronized Fast broken
tone Demodulating the wanted
signal Rx Power
Registered Solid tone Both Master and Slave units
exchanging Radio layer MAC
management messages
Rx Power
Table 9 - Audio indications from the ODU
The term ‘wanted signal’ refers to that of the peer unit being installed.
In each of the states detailed above, the unit should be aligned to give the highest pitch tone.
It should be noted that if, when in the Synchronized or Registered state, the tone varies
wildly, you may be suffering from interference or a fast fading link. Installing in this situation
may not give a reliable link. The cause of the problem should be investigated.
For the ease of alignment, both Master and Slave units use the install tones in the same way
but with some small behavioral differences. This allows the installer to install the Slave unit
first and carry out the initial alignment with the Master unit if desired. However, due to the
behavioral differences of Master and Slave units, it is recommended that the Master unit is
installed first and the initial alignment carried out at the Slave unit.
12 The pitch of the alignment tone is proportional to the received power of the wireless signals. The
best results are usually achieved by making small incremental movement in angular alignment.