Symptom: Records are taken at irregular intervals even though the trigger was previously set at something like "every 5 minutes on the 1/12 hour".
Affected models: Anything shipped before 2019-09-30
Cause: The internal Real Time Clock lost power (probably more than one week or longer) and its wake-up alarm setting was not reloaded. Loading the alarm values is normally done by changing the logging mode.
Solution:
If you do not want to install new firmware, just re-set the time in the meter, then switch the logging mode from OFF to the desired trigger which resets the wake-up alarm setting in the real Time Clock.
To plot this intermittent data without showing a broken line, select "Continuous line" from the settings section in the plotter. The broken line issue is caused because UDM guesses on where to separate different reading sessions with the break.
The proper long term solution is to upgrade the firmware which is very easy ...
Install the latest UDM (version number 239).
For Windows:
http://unihedron.com/projects/darksky/cd/Windows/For MacOSX:
http://unihedron.com/projects/darksky/cd/Mac/For Linux:
http://unihedron.com/projects/darksky/cd/Linux/The new firmware is called:
SQM-LU-DL-4-6-73.hex
The steps are:
1 Connect the meter
2 Start UDM
3 Select the found DL meter
4 Press Version button
5 Go to Firmware tab
6 Select SQM-LU-DL-4-6-73.hex
7 Press Load Firmware button
8 Wait until finished loading
9 Select the found DL meter again
10 Press Version button
11 Proceed to set your Datalogger time and trigger as before.
This will not affect your existing records in the meter.
