Vaisala WAC155 - Manual (Page 13)

Chapter 2 __________________________________________________________ Product Overview
VAISALA _______________________________________________________________________ 11
CHAPTER 2
PRODUCT OVERVIEW
This chapter introduces the features of the Vaisala Serial Wind
Transmitter WAC155.
Introduction to Vaisala Serial Wind Transmitter
WAC155
The Vaisala Serial Wind Transmitter WAC155 converts the digital data
supplied by the Vaisala 151 and 252 Series wind sensors for use in the
RS-485 bus. The WAC155 transmitter consists of a component board in
a junction box and a cross arm for mounting the wind sensors; see
Figure 1 on page 12 .
The WAC155 unit is installed underneath the cross arm, and it
communicates with the controlling system via a twisted pair RS-485
cable. The electrical connections to the sensors are 6-bit parallel gray-
code for the direction measurement and up to 750Hz digital pulse for the
wind speed measurement (anemometer).
The power to the sensors is supplied through the WAC155 transmitter.
The transmitter accepts 9 ... 15.5 VDC as input power. The WAC155
transmitter also provides the sensors with a throughput for optional
heating power. The unit automatically connects the heating power in
temperatures below +3 °C (default setting).