WindSonic Doc No 1405 PS 0019 Issue 25 February 2017
36
9.7.9 Low wind speeds (below 0.05 m/s).
Whilst the wind speed is below 0.05 metres/sec, the wind direction will not be calculated.
In both CSV mode and in Fixed Field mode, Channel 2 wind direction output will freeze at
the last known valid direction value until a new valid value can be calculated.
The above applies with the K command set for K50. If K for instance is set for 100 then the
above applies at 0.1m/s.
Wind Speed Condition
Channel 1 Speed Output
Channel 2 Direction Output
Greater Than 0.05m/s
0-5v, 0/4 – 20mA variable
0-5v, 0/4 – 20mA variable
Less Than 0.05m/s
0-5v, 0/4 – 20mA variable
Hold last known good
reading above 0.05m/s
speed until wind speed
increases above 0.05m/s
9.7.10 Error condition reporting
In both CSV and Fixed Field Modes, if a valid wind measurement cannot be calculated due
to a fault condition (for example all paths blocked), the Analogue outputs on Channels 1 and
2 can report a digital error status condition depending on the Y command setting.
NOTE:
The Y command is not applicable to WindSonic 75 Analogue output units.
WindSonic 75 units will report Error conditions as though set for Y1 below.
Y1 setting (Default).
Under data error conditions will switch back and forth between 0 and 5V (or 0/4 to 20mA) at
the selected output rate.
The following table summarises the above reporting conditions with Analogue Outputs set
for Polar Continuous Output and 0-5v (T1), 0-20mA (T5) and 4-20mA (T3).
Wind Speed Condition
Channel 1 Speed
Channel 2 Direction
Digital Error Code
Output e.g. 01, 02, 04
etc.
Cycle 0 – 5 – 0 v
at output rate
Cycle 0 – 5 – 0 v
at output rate
Cycle 0 – 20 – 0 mA
at output rate
Cycle 0 – 20 – 0 mA
at output rate
Cycle 4 – 20 – 4 mA at
output rate
Cycle 4 – 20 – 4 mA at
output rate
WindSonic Doc No 1405 PS 0019 Issue 25 February 2017
37
Y2 nnn Setting, User Set Fixed Analogue Output level in an error mode.
The unit will output a fixed Voltage (T1 setting) or fixed milli-amp (T5/T3 settings) signal
on the analogue output with a value depending on the Y2 nnn setting.
nnn is user-selectable value between 000 to 200.
Scale factor for fixed voltage output is 0.025V.
Scale factor for fixed current output is 0.1mA.
Therefore:-
nnn value = Required fixed Error Voltage/0.025 (voltage output setting T1).
nnn value = Required fixed Error Current/0.1 (current output settings T5/T3).
Under data error conditions then by setting the unit for Y2 configuration the analogue
outputs will read a user set error value for the period of the error condition as follows with
the unit in Polar Continuous Output and 0-5v (T1), 0-20mA (T5) and 4-20mA (T3).
Wind Speed
Condition
Channel 1 Speed
Channel 2 Direction
Digital Error
Code Output
e.g. 01, 02, 04 etc
Error Condition
nnn x 0.025 v (T1 setting).
Error Condition
nnn x 0.025 v (T1 setting).
Error Condition
nnn x 0.1mA. (T5 & T3 setting)
Error Condition
nnn x 0.1mA. (T5 & T3 setting)
Y3 nnn setting Analogue Output cycles to a user determined level in an error mode.
Under data error conditions the analogue outputs will switch back and forth between a user
determined level (voltage or current) with a value depending on the Y3 nnn setting.
nnn is user-selectable value between 000 to 200.
Scale factor for upper voltage output is 0.025V.
Scale factor for fixed current output is 0.1mA.
Therefore:-
nnn value = Required Error Voltage/0.025 (voltage output setting T1).
nnn value = Required Error Current/0.1 (current output settings T5/T3).
The following table summarises the above reporting conditions with Analogue Outputs set
for Polar Continuous Output and 0-5v (T1), 0-20mA (T5) and 4-20mA (T3).
Wind Speed Condition
Channel 1 Speed
Channel 2 Direction
Digital Error Code
Output e.g. 01, 02, 04
etc.
Cycle 0 – set v – 0 v
at output rate
Cycle 0 – set v – 0 v
at output rate
Cycle 0 – set mA – 0 mA
at output rate
Cycle 0 – set mA – 0 mA
at output rate
Cycle 4 – set mA – 4 mA
at output rate
Cycle 4 – set mA – 4 mA
at output rate