Instruction Manual
The following diagram depicts the four different alarm conditions, as well as the 
corresponding hysteresis levels that must be reached to clear the alarms generated for each 
condition, in a line chart. 
Please note that the diagram uses enumerations to label the hysteresis levels the input value 
must reach for each alarm status to be cleared. For example, AL_HIGH_LMT_CLR_2 
represents the value necessary to clear the AL_HIGH_LMT_ALM_2 alarm status. 
AL_HIGH_LMT_CLR_1 represents the value necessary to clear the AL_HIGH_LMT_ALM_1 
alarm status. The data points in your network will not be updated to these statuses at any 
time. 
AL_HIGH_LMT_ALM_2 
CompValue + 
UCPThighLimit2Offset= 
AL_HIGH_LMT_ALM2 
CompValue + 
UCPThighLimit2Offset 
 - SCPThystHigh2 
AL_HIGH_LMT_CLR_2 **
  AL_HIGH_LMT_ALM_1 
CompValue + 
UCPThighLimit1Offset= 
AL_HIGH_LMT_ALM1 
CompValue + 
UCPThighLimit1Offset 
- SCPThystHigh1 
AL_NO_CONDITION 
AL_HIGH_LMT_CLR_1 **
CompValue 
AL_LOW_LMT_CLR_1 **
Input Value 
CompValue – 
UCPTlowLimit1Offset 
+SCPThystLow1  
AL_LOW_LMT_ALM_1 
CompValue - 
UCPTlowLimit1Offset= 
AL_LOW_LMT_ALM1 
AL_LOW_LMT_CLR_2 **
CompValue – 
UCPTlowLimit2Offset 
+SCPThystLow2 
CompValue - 
UCPTLowLimit2Offset= 
AL_LOW_LMT_ALM2 
AL_LOW_LMT_ALM_2 
Figure 1 Hysteresis Levels and Offset Limits 
i.LON 100 Internet Server Programmer’s Reference  7-15 










