4) When the AIR-485 Master is connected to a PC via USB it is powered from the USB port.
Because of the limited current available, only the two lowest power setting should be
used. If a higher transmit power setting is required, you need to use an optional plug- in
power supply.
5) Switch 1
– For Point To Point, set one unit to Master and the other to Slave. If one is
connected to the PC via USB, it must be set to Master. For Multi-Point, set the unit
connected to the PC (via RS-485 or USB) as Master and set the field units as Slaves.
6) Switches 2 and 3
– The factory default setting is Low Power. If the distance between the
Master and Slave(s) is MORE THAN 100 feet, set the switches to HIGH POWER on
both the Master and Slave(s). Note that the Master and Slave(s) should always be set
to the SAME power level. If the distance from the Master to the Slave(s) is LESS THAN
100 feet, start with both units set to LOW POWER and progressively increase the power
level until you get an acceptable signal level (see Signal Level Test below). This is
important as using a power setting that is too high for a Master and Slave which are in
close proximity will result in a poor communications link.
7) Switch 4
– Set to DOWN (default) for North America. Set to UP for Australia.
8) Switch 5
– Used to set the hard wired baud rate. The baud rate through the air is fixed
and is 115K bps.
9) Switch 6
– Must be DOWN.
10) Switch 7
– Applies to Slave units only. When this switch is UP, the unit is in Signal Test
Mode. In this mode, the Slave unit interrogates the Master which returns a diagnostic
message which allows the to measure the received signal. The three green LEDs
display this relative signal strength (see below).
11) Switch 8
– Must be DOWN.
