9. Troubleshooting
9.1 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.
Table 14 Troubleshooting Table
Problem
Possible Causes and Solutions
One of the following occurs:
• Transmitter outputs stars "****" on serial line
instead of measurement data.
• Unavailable value in Modbus mode.
• Analog signal is at error level.
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 Vaisala Insight PC software or 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 or MODBUS mode
with unknown address.
Check wiring. Check communication settings
with Vaisala Insight PC software. Try connecting
as instructed in section
Interface in Devices with Modbus Output
(page 42)
.
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 Vaisala Insight PC
software or the
ERRS
command. Wait for the
diagnostics to complete.
Dew point alarm LED is red even though the
measured dew point is not high.
Possible causes: the alarm limit may be set
incorrectly for your application.
Check and correct using Vaisala Insight PC
software, serial line, or MI70 indicator.
More Information
‣
Vaisala Insight Software (page 36)
‣
Connecting to the Serial Interface (page 41)
‣
DMT143 User Guide
M211435EN-J
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Summary of Contents for DRYCAP DMT143
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