Page 50
DH3 WIRELESS GATEWAY
USER GUIDE
27.
TRENDING (DATA LOGGING)
DH3’s trending function is a time-based logging system. Up to 800,000 points max
can be logged regardless of storage capacity of internal RAM or connected Micro
SD Card. Thus, the number of registers and sampling frequency determines the
maximum range.
If event-based logging function is required, then use DH3’s event logging
capabilities described in the previous section.
Any point available in the DH3 Import tab can be used for trending based on a set
interval. Data trending provides continuous data recording. It is also possible to
record multiple trends.
Only at boot up, DH3 automatically detects if a Micro SD Card is present and will
write to it, providing non-volatile or persistent data. If Micro SD Card is not
detected, it will write to internal RAM, but data stored on RAM is volatile and will
be lost when DH3 is power cycled or updated. If Micro SD Card is removed while
operating, DH3 will switch and write to RAM. If any critical data is written to RAM,
exporting the .csv file is recommended prior to re-booting or updating DH3.
DH3 Serial Number 0178730001 and higher are equipped with a Micro SD Card
slot. Use only OleumTech Part Number SX1000-SD2 Industrial-grade Micro SD Card
for data logging.
Use Formula to Determine Max Range:
800,000 / (points * (86400 / interval secs))
DH3 internal clock must be setup properly.
see sec. 28
Use DH3 Web Server to view trends/graphs.
see sec. 28
Using Web Server, a trend can be exported as PDF or PNG file.
Database can be exported to .csv file using BreeZ®.
1.
Double-click on DH3 in project tree
2.
Click on Imports tab
3.
Select desired point(s) to be part of data trending
4.
Right-click over the highlighted area and select Trending
Click here to use trending calculator