Vaisala WS425 - Manual (Page 74)

USER'S GUIDE____________________________________________________________________
74 __________________________________________________________________ M210361EN-E
frequency range spanned from 10 kHz to 10 GHz. The tested sensors
were only disturbed by frequencies occurring at the band from 95kHz to
107kHz, which is the range that the sensor uses for the ultrasonic
measurement. Radio communication devices do not operate at this band.
Despite the heavy testing, the GSM link equipment may cause
interference to an ultrasonic sensor due to extremely high
electromagnetic field levels around the transmission antenna. In this type
of installation, a small displacement of the sensor may completely
remove an interference problem that occurs at a certain point of the mast.
Trial and error is really the only way of finding out whether RF
disturbance will be an issue.
Q:
I have tried out my WS425. When I turn the power on the sensor is not
sending any data. I used an RS-232 checker but the Tx line is not active
(no data is coming to my PC).
A:
By default, the sensor is set to a command-response mode (polling
mode). This means that the sensor is waiting for a data request command
from the data logger. If you want the sensor to automatically send data
through the serial line, you need to open a maintenance connection to
your WS425 sensor and configure parameter number 5, Output Interval,
to have a non-zero value. In order to open a maintenance connection, see
the attached procedure on the next page.