Queue Full Alarm; Sample Rates - Honeywell CNI2 Operating And Installation Manual

CNI2 Operating and Installation Guide
The time interval can be anything evenly divisible into 60 minutes. A shorter time period allows
you to observe small changes with more detail. But it also consumes memory more quickly,
causing the CNI2 to need to communicate with the data collection system more frequently so
that older data is not lost. This can have an impact on both battery life and the cost of the
cellular service.
The CNI2 can save a total of 30,000 records before it starts to overwrite the oldest records.
These are divided equally between all active pulse-counting channels. If only one channel is
used for pulse-counting then all 30,000 record locations will be used for that channel. If using a
10-minute interval it would take a little over 200 days to reach the end of the memory. If three
channels are active then each channel is allocated 1/3 of the memory, or 10,000 records.
Each record consumes 2 bytes of memory. For a queue size of 30,000 records select the "60K"
size. For a smaller queue (16,000 records) select the "32K" size. The data collection system
® ®
(DC-2009 or MV90 ) has the ability to request the entire contents of the queue, so a smaller
queue size will result in a shorter call, lower power consumption and lower cellular costs.

Queue Full Alarm

To prevent the loss of accumulated data the CNI2 will place an immediate call to the central
office when the storage "queue" reaches a certain point. You can define this as any percentage
between 1% and 100%. Default is 75%.

Sample Rates

The CNI2 does not inspect the state of the inputs 100% of the time; otherwise it wouldn't have
time to perform any other functions. Rather the CNI2 briefly inspects ("samples") the condition
of the lines one or more times each second. You can configure the CNI2 to take as few as one
sample per second or as many as 50 samples per second. The 12 possible input/output lines
are divided into two groups, each with its own sampling rate. Lines-1, 2, 9, 10, 11 and 12 are
one group. Lines-3 thru 8 are in the other group.
NOTE
Lines #3 thru #8 are only available using an optional expansion board which is not available
at this time.
The sample rate is based on how quickly you expect the inputs to change. Faster sampling
rates are used for quickly-changing inputs but results in higher power consumption. Too slow
of a sampling rate can lead to errors.
Debouncing and sample rates are discussed in more detail later in this document.
76