Pwd22 Reports Frozen Precipitation During Rain; Pwd22 Electrical Troubleshooting - Vaisala PWD22 User Manual

Chapter 7_____________________________________________________________ Troubleshooting
VAISALA _______________________________________________________________________ 103
PWD22 Reports Frozen
Precipitation during Rain
The ratio of optical intensity measurement to the RAINCAP
measurement is too high.
1. Check the optical calibration and RAINCAP
2. If everything else seems to be functioning correctly, change the
parameter settings.
- If possible, check the accumulated water sum against a
reference rain gauge. This will indicate how close the Rain
intensity scale is to the optimal value. Decrease the scaling
factor if the PWD22 rain amount is too high.
- Otherwise, increase RAINCAP
command).

PWD22 Electrical Troubleshooting

PWD22 is protected against reverse polarity connected to power feed
wires. If the power feed is connected to other leads than those for
power supply, damage may occur depending on feed voltage and
current limiting features of the supply.
If there is no response from PWD22, do the following:
1. Check the connections. PWD22 diagnosis can be done through
the RS-232 maintenance line.
2. Check the baud rates:
- The factory default is 9600,7,E,1.
3. Open the cover of the receiver.
4. Connect the power and watch the internal LEDs.
Initialization sequence (3 seconds):
LED 4 RED lit (Signal lit / offset off)
LED 3 YEL lit (RUN, 1 Hz)
LED 2 RED off (Transmit Data)
LED 1 YEL off (Receive Data)
Start sequence (1 second):
LED 4 RED lit (Signal lit / offset off)
LED 3 YEL off (RUN, 1 Hz)
®
®
operation.
®
scale (the WSET