YSI IQ SensorNet 2020 XT Terminal - Manual (Page 23)

System 2020 XT USB Overview
1 - 17 ba76019e01 12/2012
1.3.5 Status LED
The status LED informs you of the state of the system:
Status LED Meaning
Permanently
on – The IQ S ENSOR N ET is running fault-free
Permanently
off – No power supply
Flashes – The IQ S ENSOR N ET discovered an alarm.
– The IQ S ENSOR N ET discovered an error, e.g.:
– A communication error in the IQ S ENSOR N ET
– An invalid measure value
– The backup controller has assumed controller
function
The LED flashes as long as the error is present
(even if the log book message of the error has
already been acknowledged). More detailed
information on the error is given in the log book.