Vega SI-21 / User Manual
Revision 11 – 23 October 2020
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5 COMMUNICATION PROTOCOL – VERSION 2.0
This part describes the last version of the communication protocol for SI-21 data
exchange with LoRaWAN network. You can see the device protocol version number in the
“Configurator” application in the “Device info” tab.
In fields consisting of several bytes, the little-endian byte order is used
VEGA SI-21 PULSE COUNTER TRANSMITS THE FOLLOWING TYPES OF PACKETS
1.
Packet with current readings, sent regularly on LoRaWAN port 2
Size in bytes
Field description
Data type
1 byte
Packet transmitting reason
uint8
1 byte
Battery charge, %
uint8
4 bytes
This packet time (unixtime UTC)
uint32
2 bytes
Temperature in
°
С multiplied by 10 (sign value)
int16
4 bytes
Input 1 reading (depending on the type – number of pulses or
status: 0 – open, 1 - closed)
uint32
4 bytes
Input 2 reading (depending on the type – number of pulses or
status: 0 – open, 1 - closed)
uint32
4 bytes
Input 3 reading (depending on the type – number of pulses or
status: 0 – open, 1 - closed)
uint32
4 bytes
Input 4 reading (depending on the type – number of pulses or
status: 0 – open, 1 - closed)
uint32
1 byte
Temperature is out of range («0» - NO, «1» - OUT OF RANGE)
uint8t
1 byte
Low temperature threshold (from -128
°
С to +127
°
С)
int8t
1 byte
High temperature threshold (from -128
°
С to +127
°
С)
int8t
If the thermistor is not connected to the pulse counter (contacts “Therm”
and “
”), in the “Temperature” field the -100 °C value will be sent for
breakage or fault indication
When there is a short circuit of the thermistor, the value -127 °C will be sent
in the “Temperature” field
The counter has internal clock and calendar; time and date on which are factory preset or
may be corrected during the exploitation. Forming of packets with the current readings is
going on for the time moments, which is multiple to the set data collection period:
•
1 hour period: the readings of the beginning of the current hour are sent;
•
6 hours period: 00:00, 06:00, 12:00, 18:00 readings are sent;
•
12 hours period: 00:00, 12:00 readings are sent;
•
24 hours period: the readings of 00:00 of the current day are sent.