Vaisala LT31, Руководство пользователя, Страница: 119 / 294

Chapter 4 _______________________________________________________________ Installation
VAISALA ______________________________________________________________________ 119
0401-099
Figure 80 Connecting PWD
4. All necessary electrical connections in the interface unit are already
prepared.
5. Remove the ladder.
Connecting Signal Lines to Transmitter Interface
Unit
1. Open the interface unit box.
2. Wire the cables through the cable feed-throughs at the bottom of
the box.
3. Make the connection of cables that are shown circled in Figure 81
on page 120.
4. The interface unit of the transmitter must be connected to the
two-wire RS-485 module bus (terminals 8 and 10) which connects
all intelligent modules within the LT31 system with each other. In
addition, a two-wire synchronization line (terminals 6 and 7)
connects the modulation clock between the transmitter and
receiver.
NOTE The cable shield must be properly grounded in the cable gland of the
interface unit enclosure. See Figure 35 on page 77.