Vaisala LT31, Руководство пользователя

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User's Guide ______________________________________________________________________
128 _________________________________________________________________ M210667EN-C
computer system. For details on different interface types and settings, see
section Communication Options on page 78.
Connecting Communication and Power Cables
Connecting Communication Cable to Receiver Interface Unit
The receiver interface unit is equipped with the master CPU LTC212.
This CPU is responsible for communication with all intelligent units
within the LT31 system and for the communication with the host
computer system.
1. Connect the respective data terminals of the interface unit with the
recommended communication cable type, see section Cable
Selection on page 73. The communication cable should be either
connected into the Vaisala TERMBOX (see above) or routed
straight through the opening in the base plate of the mast and
further into a local junction box. Prepare a cable of sufficient length
to interconnect the interface unit with the local junction box.
2. Route the cable through a fitting cable feed-through at the bottom
of the interface unit.
3. For details, see section Communication Options on page 78.
Connecting Power Cable to Receiver Interface Unit
The power cable should be either connected into the Vaisala TERMBOX
(see above) or routed straight through the opening in the base plate of the
mast and further into a local power distribution box. Use a 3-conductor
power cable (3 x 1.5 mm
2
) of sufficient length with free wire ends. Make
sure to connect the wires in the correct way, especially the ones to the
protective ground (usually yellow/green). See Figure 84 on page 126 for
wiring instructions.
Switching on LT31 System
After the wiring work is finalized, the common power for the receiver
and transmitter location can be switched on and the power switches
inside the interface unit enclosures of the transmitter and receiver can be
switched on as well.
In case the battery backup LTBB111 is installed, the battery switches can
now be switched on as well on both locations
.
The LEDs on the power supply of the interface unit must illuminate. See
Figure 85 on page 129 and Figure 86 on page 129.