Vaisala HMT120 - Manual (Page 70)

User's Guide _______________________________________________________________________
68 ___________________________________________________________________ M211244EN-B
Solving Typical Problems
You can check the error message via the serial interface by using the
ERRS command; see section Error Codes on page 67. In case of
constant error, please contact Vaisala Technical Support.
Table 8 Troubleshooting Table
Problem or Message Likely Causes and Solutions
Measurement not working, any of
the following errors is active:
- Probe RH measurement error
- Probe T measurement error
- Sensor(s) damaged or missing. Open the
probe filter and check.
- Calibration is not done. Calibrate the probe.
- Check the supply voltage of the transmitter.
Transmitter cannot communicate
with the probe, any of the
following errors is active:
- Probe communication error
- Probe checksum error
- Probe message form error
- Measurements not available
- Check the attachment of the probe to the
transmitter.
- In case of remote probe, check also the
interconnection cables.
- Replace the probe if necessary.
Serial line command not working,
outputs "Unknown command."
- Mistyped or unknown command, check the
command syntax and parameters.
Cannot connect to serial line,
current serial settings of the
module are unknown.
Perform the following steps to connect:
1. Set your terminal settings to 19200 8 N 1
(the default settings of the transmitter).
2. Connect to the service port of the
transmitter.
2. Power up the transmitter, and type "Z" on
the serial line at least five times.
4. The transmitter will come online with the
default settings.
5. Use the SERI command to set the desired
serial settings, and use the SAVE
command to save them.
Any of the following errors is
active:
- Current settings checksum error
- Default settings checksum error
Internal error. Perform the following steps:
1. Reset or power cycle the module. Check if
the error disappears.
2. Return the module to factory settings using
the FRESTORE command. Check again.
3. If the error is still active, contact a Vaisala
service center.
Any of the following errors is
active:
- Program checksum error
- Factory flash defaults checksum
error
- Factory flash not initialized
- Oscillator fault bit active
Faulty transmitter, contact a Vaisala service
center.
Any of the following errors is
active:
- Analog output quantity invalid
- Display quantity invalid
In case of "Analog output quantity invalid"
error select the correct output quantities (set
with the CALCS command) with ASEL
command and in case of "Display quantity
invalid" error select the correct display
quantities with DSEL command.