IWM-LR3 - IWM-LR4
User Manual v1.0
9
Vif and management of counters
If the index K = 1 (liters) [where K=1 means
CPR-M3-I
,
GMDM-I
,
GMB-RP-I
,
GMB-I
; K=10
WDE-K50
up to DN125
included; K=100
WDE-K50
DN150 and DN200], the initial value of VIF = 0x13 (liters) is considered. If the meter
exceeds the maximum number of countable liters (99.999.999), the counter is incremented and not reset
(100,000,000 liters) and the new counting value will be 10,000,000 decaliters with VIF = 0x14 (decaliters).
Consequently, the counter will be increased by one unit every 10 turns of the target.
If the index K = 10 (liters), the initial value of VIF = 0x14 (decaliters) is considered. If the meter exceeds
the maximum number of countable decaliters (99.999.999), the counter is increased and not reset to zero
(100,000,000 decalitres) and the new count value will be 10,000,000 hectoliters with VIF = 0x15 (hectoliters). If
K = 100 (liters) I transmit with VIF = 0x15 (hectoliters) and then use VIF = 0x16 (m3) at the time of the counter
overflow.
In the case of further overflows, the VIF is decreased by a size and the counter reset to 0.
Alarm byte coding
Bit 0: Magnetic
Bit 1: Removal
Bit 2: Sensor fraud
Bit 3: Leakage
Bit 4: Reverse flow
Bit 5: Low battery
Temperature byte coding (extra)
Temperature reading can be enabled with a 0x26 SET_ALARM_PAR command (NFC or LORA). The parameter
is in the most significant byte of block 6A of the EEPROM.
Eg. 26 00 00 00 09 04 00 00 00 01 00 00 00 00
→
Enable
Eg. 26 00 00 00 09 04 00 00 00 00 00 00 00 00
→
Disable
N.B:
Pay attention to the meaning of the other parameters (for example the last 4 bytes are the low battery
threshold). Refer to the supplement ‘integrators’ document: request it directly from B METERS.
In the payload with Temperature parameter enabled there are at the bottom two additional bytes that indicate
the temperature. Refer to the example below.
Eg.
01 1b
(HEX) means 283 (decimal) which, like the rest of the fields by convention, must be interpreted as
28.3 (the28.3° C).
The negative temperature value is indicated by the most significant bit at 1 of the first (from left to right) of
the two bytes that give the temperature value (0x80 in the example below). The remaining 15 bits indicate the
absolute value.
Eg.
80 be
(HEX)
→
be
→
19 (decimal) so –19° C
