Vaisala WMT700 - Manual (Page 143)

Chapter 5 _________________________________________________________________ Operation
Wind Speed Output
In a system configured for WS425, you can set WMT700 to
measure wind speed and send analog output as frequency or
voltage.
These sections describe WMT700 analog output:
- Settings are configured according to Table 42 on page 140.
- Wires are connected according to section ROSA Cable 10 m
(Analog Outputs) on page 100.
Frequency
When frequency is selected as the wind speed analog output,
WMT700 sends a pulsed signal of 0 to 10 V with a frequency
proportional to wind speed through AOUT1. Every mile per hour
adds 5 Hz (WS425) to the frequency. In SI units, a change of
0.894 meters per second adds 10 Hz to the frequency.
A frequency counter is required to count the output in Hz and the
calculation that scales the result to appropriate units.
Figure 48 below shows the frequency output when an adapter
cable for analog frequency output (227570SP) and a WS425 cable
are used. With WMT700, the wind speed signal appears at pin 14
(pink) of the adaptor cable.
1212-001
Figure 48 Wind Speed Frequency Analog Output with
WS425 Cable and Adapter Cable for Analog
Frequency Output
VAISALA _______________________________________________________________________ 141