•  Sensor temperature average in ˚C. 
•  Readings or output of optional I/O #1 to #4. 
 
Navigation is performed as follows: 
1.  From Short Term History, press Enter to read the date and time of the last event 
recorded in the Short Term history file. 
2.  Press the Up or Down arrow keys to read the date and time of previous or next 
recordings. 
3.  Press Enter and the Up or Down keys to read the value  of the  variables at the 
selected date and time. 
3.4.2.2  Long Term History 
The Long Term History function gives access to the Long Term history file.  From 
one  to  four  times  per  day  (adjustable;  see  parameter  Long  Term  Rate  in  Setup  > 
History  Setup  >  History  Log  Rate  [see  Section  3.2.6.1]),  the  date  and  time  plus 
several values are stored in this file.  Its capacity is 4,760 records (if equipped with 
four analog input interfaces); when the file is full, a new record erases the oldest one 
in a first in, first out method. 
Navigation in this file is performed as in the Short Term history file.  The values 
recorded in the Long Term history file are also identical.  See Section 3.4.2.1. 
3.4.2.3  Event History 
The Event History function gives access to the Events history file.  When an event 
occurs, the date and time of occurrence, an event message and several values are 
stored in this file.  Its capacity  is 3,120  records (if equipped with four analog input 
interfaces); when the file is full and a new recording occurs, the oldest recording is 
deleted  (first  in,  first  out  method).    All  event  messages  and  their  description  are 
provided in Appendix H. 
The following events are recorded: 
•  An alarm is triggered. 
•  An alarm is acknowledged by a user. 
•  An alarm is cancelled (the alarm condition has disappeared). 
•  A parameter is changed by a user. 
•  The date and time are set. 
•  A new sensor is installed. 
•  The Hydran M2-X is calibrated. 
•  A power-up or a shutdown occurs. 
•  The Hydran M2-X is put in service (first power-up). 
•  The self-test sequence has failed during power-up. 
•  The microprocessor is reset by the internal watchdog.