19 No such device
23 Too many open files in system
24 Too many open files
26 Text file busy
28 No space left on device
32 Broken pipe
101 Network is unreachable
110 Connection timed out
111 Connection refused
113 No route to host
129 Illegal Function (function was not allowed by the slave device)
130 Illegal Data Address (the data address is not allowed by the slave device)
131 Illegal Data Value
132 Illegal Response Length
139 Device Failed to Respond (the Modbus device may be off or disconnected)
140 Received invalid Modbus data checksum
160 Start log (Entry in log file after Energy Monitoring Hub starts up)
161 Stop log (Entry in log file if Energy Monitoring Hub is shut down properly)
162 System time changed, caused logger to restart logging for intervals.
163 System auto-restart
164 Log entry corrupt.
165 Modbus device restart detected.
192 Modbus device does not match the device type in the configuration file.
193 Modbus device's serial number changed. (could be two devices with the same Modbus address)
Low/High Range Alarms:
This number is a hex representation showing which data points are out of range. 0x01 shows
data point 1 in alarm state. 0x04 shows data point 3 in alarm state.
Data Points:
Data points are shown in the same order as the Modbus device configuration display in the Modbus/device list
page. Data is displayed in floating point form. When a specific point is unavailable (4A4P-M broken wire alarm) or the
point is not supported as part of the configuration (phase B current on a single phase H8163 meter hookup) the point will be
logged as blank. This preserves the column structure of the file, and allows notation of invalid data. SQL databases often
accept blank or NULL as a valid entry in a data table to represent invalid data.
For data exported from the LEM website, the columns that are invalid (NULL) are reported as blank fields. This makes it
easier to import into MS Excel as blank cells. With the current firmware, the Energy Monitoring Hub will report blank fields
rather than "NULL" to make direct import of data from the Energy Monitoring Hub easier, as well as reduce the file size.
Developers intending to use data files from the Energy Monitoring Hub should handle both the word "NULL" as well as a
blank column as indications of an invalid data point.
Log Storage Capacity
The Energy Monitoring Hub uses approximately 8 Mbytes of flash disk for log file storage. As data from the Modbus
meters is collected, it is appended to log files on this flash chip. Once a day (at the first call-out period for uploading data)
the log files are "rotated". This action renames each log file and compresses the old file using gzip. The net result is a
smaller file for storage or modem/Ethernet transfer.
Because the files are compressed, the actual size of the data on the flash chip will vary depending on the data itself. For
example, if a device is reporting 25KWh, it will use fewer bytes than a log entry that has 9,999,999KWh.
We have measured a typical installation with 5 H8036 power meters and 5 A8923 IO modules, and determined the system
will run for well over a hundred days with a 15 minute log cycle. Changing the number of meters, the type of log data, or the
log cycle period will affect your results accordingly.
When the Energy Monitoring Hub storage area on the flash starts to run out of space, the following action is taken:
When the 8 Mbyte log file storage area is 75% full, the Energy Monitoring Hub will immediately compress the log
files and attempt to upload the data to the LEM website or user specified site. This action will not wait until the
next scheduled upload time.
When the storage area is 95% full, the Energy Monitoring Hub will immediately attempt to upload the data, and if
unsuccessful, will purge the oldest (rotated) log data file.
Shop for Power Metering products online at:
1.800.561.8187
www.
PowerMeterStore
.ca