USB-502-LCD LED functions
USB-500 Series Data Loggers
11
Red/Green
LED (%rh)
Red/Green
LED (°C/°F)
LCD button
LCD
USB-502-LCD LED functions
The USB-502-LCD has two LEDs—each of which flash either red or green. One
LED represents temperature (ºC/ºF), and the other relative humidity (%rh). An LED
flashes red to indicate an alarm reading. The LCD can display temperature and
humidity data all of the time or when the LCD button is pressed, depending on its
configuration.
Green
LEDs
When a green LED flashes
once
every 10 seconds, the USB-502-LCD is
logging with no
alarms. The last stored readings are within the set alarm limits.
No action is needed.
When a green LED flashes
twice
every 10 seconds, the USB-502-LCD starts logging at the
date and time you have set.
When a green LED flashes
three times
every 10 seconds, the USB-502-LCD's memory is
full and it can store no more readings
.
You need to download data from the device.
If
Hold
is selected, a flashing green LED indicates that no alarm condition has been logged
during the current logging session.
Red LEDs
When a red LED flashes
once
every 10 seconds, the USB-502-LCD is
logging with a low
alarm
.
The action you take depends on your application.
When a red LED flashes
twice
every 10 seconds, the USB-502-LCD is
logging with a high
alarm
.
The action you take depends on your application.
When a red LED flashes
three times
every 10 seconds, the USB-502-LCD has an alarm
condition and its memory is full
.
You need to download data from the device.
When the red LEDs simultaneously flash
once
every 60 seconds, the USB-502-LCD's
battery charge is low. The device continues logging, but alarm conditions are ignored. You
need to replace the battery and then download data from the device.
If both alarms have
Hold
selected, the alarm condition may have been triggered at any point
during the current logging session.
No LEDs
When no LEDs are flashing, plug the USB-502-LCD into the PC and run the USB-500
software to find out which condition applies. If logging is not set up, then set up logging. If the
battery is depleted, then install a new battery.
