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Item Offset
(Bytes)
Length
(Bytes)
Description
Version 0 1 Error log version number. Currently 1.
Entry size 1 1 Size of each error log entry
Entry count 2 1 Current number of error log entries
Latest entry 3 1 Index of latest error log entry
Sequence 4 2 Incremented for each additional error log entry
Error log entries 6 Entry size *
Entry count
(Entry count) SNVT_alarm_2 records
To compute the time at which an alarm in the error log occurred, first compute the
alarm time by using the alarm_time and milliseconds fields from a particular error
log record. The record format is SNVT_alarm_2. Then read the nvoElapsedTime
network variable. Using the difference, subtract that time from the local time of day.
Don't forget to factor in daylight savings time, if applicable.
Since direct memory commands are used to read the log, it is possible that the
Monitor will be updating the log while a network management tool is reading it. In
order to ensure that reads are consistent, read the error log only after all of the
Channel Monitor functional blocks are temporarily disabled.
Channel Monitor Functional Blocks
Network Variables
Each of the five Channel Monitor functional blocks collects information about the
number of errors and number of messages on the associated externally-connected
channel. This information is used to update the Status LEDs described in LED
Legends in Chapter 2, and this information is also available on the network through
the following network variables:
Note: The programmatic Network Variable name appears first. The LonMaker
Channel Monitor's Network Variable shape name is located under it, in parentheses.
Network Variable Type Description
nvoIvalBandUtl
(Last Bandwidth
Use)
SNVT_lev_cont
Percentage of bandwidth being used
in the last interval. This variable is
alarmed. See the section Alarms
below for details.
nvoIvalPackets
(Last Packets)
SNVT_count_32
Number of messages received in the
last interval.
MPR-50 Multi-Port Router User's Guide 27