5. LoRaWAN Data Upload Formats
4.3.3. Cron expressions
Cron expressions are used to dene specic points in time and regular repetitions of them.
The schedule for data collecting phases is dened using the Cron
format which is very
powerful format to dene repeatedly occurring events
Standard Lobaro devices typically do not need to know the real time for proper opera-
tion. All times are relative to the random time when batteries are inserted. If needed
by the target application Lobaro can deliver on request special hardware support for keeping
data acquisition intervals based on a real time clock which stays in sync with the real time.
Please contact Lobaro directly if you need such a custom product variant.
A cron expression consists of 6 values separated by spaces:
Seconds (0-59)
Minutes (0-59)
Hours (0-23)
Days (1-31)
Month (1-12)
Day of Week (SUN-SAT
b
= [0,6])
Examples of CRON denitions:
0 5 * * * *
Hourly at minute 5, second 0 (at 00:05:00, 01:05:00, ...)
0 1/10 * * * *
every 10 minutes from minute 1, second 0 (minutes 1, 11, 21, ...)
0 0 6 * * *
Daily at 6:00:00
0 0 13 1,15 * * 1st and 15th day of every month at 13:00:00
0 0 9 1-5 * *
Every month daily from day 1 till 5 at 9:00:00
5. LoRaWAN Data Upload Formats
After collecting wireless M-Bus telegrams over the air, the Bridge starts uploading data
via LoRaWAN. There exist two data formats that are transmitted over dierent LoRaWAN
ports.
As LoRaWAN can only transmit very short messages, the message formats contain only data
bytes. The meaning of a byte is determined by its position within a message. The following
describes the package formats used by the wireless M-Bus Bridge.
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For more information about Cron see
https://en.wikipedia.org/wiki/Cron
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Online introduction:
https://github.com/lobaro/docs/wiki/CRON-Expressions
wMBUS over LoRaWAN Bridge
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