Vaisala DMT143 - Manual (Page 67)

Chapter 7 ____________________________________________________________ Troubleshooting
VAISALA ________________________________________________________________________ 65
CHAPTER 7
TROUBLESHOOTING
This chapter describes common problems, their probable causes and
remedies, and provides contact information for technical support.
Solving Typical Problems
Some problems can be solved by simply resetting the transmitter. You
can reset the transmitter by disconnecting the power or issuing the
RESET command using the service port.
If resetting does not help, and if the problem is related to transmitter
software or settings, you can restore the factory configuration of the
transmitter by issuing the FRESTORE command. If you are unable to
solve your problem with the transmitter, contact Vaisala technical
support. See section Technical Support on page 67.
Table 12 Troubleshooting Table
Problem Possible Causes and Solutions
Transmitter outputs stars
"****" on serial line instead
of measurement data Possible causes: damaged sensor, incorrect
supply voltage, and unsuitable measurement
environment.
Power cycle or reset the transmitter, and see if the
problem continues. Check the active errors using
the ERRS command. Check the power supply.
Unable to access
transmitter on the RS-485
line. Possible causes: Incorrect wiring, unknown serial
settings, transmitter in POLL mode with unknown
address.
Check wiring. Try connecting as instructed in
section Unknown Serial Settings on page 66.
Issue the ?? command to make the transmitter
respond in POLL mode.
Analog output seems to
be stuck, the
measurement is not
changing. Possible causes: Sensor diagnostics in progress
(autocal or purge), malfunction error active.
Check the active errors using the ERRS
command. Wait for the diagnostics to complete.
Dewpoint alarm LED is
red even though the
measured dewpoint is not
high. Possible causes: the alarm limit may be set
incorrectly for your application.
Check and correct using serial line or MI70
indicator.