Manual – 3000 NRL Family
Unidata Manual - 3000 NRL Family - 17 09 2018.docx
Page 10
2.2 3004M
“Low
End”
These loggers have three bi-colour (red/green) LEDs:
Label Description
PWR
Same as the Power LED described above.
SCHM
Same as the Scheme LED described above.
COMS
A combination of the Config, Neon, and Status LEDs described above. If any of
those LEDs would be green, this LED will be green. Otherwise, if any of those
LEDs would be red, this LED will be red. If all of those LEDs are off, this LED
will be off.
2.3 Normal
Scheme
Indication
In normal operation the Power/PWR LED comes on first, quickly followed by the
Scheme/SCHM LED, then both turning off. This occurs at regular scan intervals as
specified by the scheme, which can range from one second to many minutes.
At each interval the Power/PWR LED is turned on for the duration of the scan, which is
typically less than a second, and is when the various logger inputs are read and the
scheme program executed.
The scheme also operates during each scan, after the sensors have been read. While the
scheme is executing, the Scheme/SCHM LED is lit. The colour of the LED is under
scheme control, but by default green indicates correct operation.
Unless the logger is communicating, no other LEDs will be lit.
2.4 Telemetry
Indication
When the logger communicates with Neon, the Neon/COMS LED will be lit. It will start red
until a connection is established with Neon, at which time it will turn green. When the
communication process completes, the LED is turned off.
2.5
Direct Connection Indication
If you are using the USB port to directly connect to the logger, then the Config/COMS LED
will turn red when the logger detects a cable has been connected. When the logger
receives a command it recognises, it will turn the LED green to indicate a successful
connection. If no commands are quickly received, usually within half a second, the logger
will turn the port off to conserve power. It will also turn the port off when instructed by a
connected computer. It will check the port again after a few seconds.
As a result, the LED will blink red when a cable is plugged in, but the software is not
communicating. If the software is communicating, the LED will briefly light red before
changing to green when the logger received the first command. It will stay green while the
software is communicating (for example, updating test displays, or programming or
unloading the logger), then turn off when the software is finished.