Raw energy counters tell you how much energy was consumed in total. But utilities need to know when it was consumed, what happened during power outages and tamper attempts, and exactly how much to bill at the end of each month. This is what load profiles, event logs, and billing registers provide.
Load Profile
A load profile is a time-series record of energy and power parameters captured at fixed intervals — typically every 15 or 30 minutes. Think of it as a detailed diary of the meter's measurements.
Each record in the load profile (called a capture entry) typically contains:
- Timestamp
- Active energy import (kWh)
- Active energy export (kWh, for solar/DG)
- Reactive energy (kVArh)
- Apparent energy (kVAh)
- Maximum demand in the interval
In COSEM, the load profile is stored as a Profile Generic object (Class ID 7). The object has a capture object list that defines which COSEM objects are recorded at each interval.
Billing Registers
At the end of a billing period (typically monthly), the meter takes a snapshot of all energy counters. These snapshots are stored as billing registers and are the authoritative source for generating the customer's bill.
| Register | OBIS Code | Content |
|---|---|---|
| Current billing period kWh | 1.0.1.8.0.255 |
Active energy import, running total |
| Previous billing period kWh | 1.0.1.8.0.1 |
Snapshot at last billing date |
| T1 kWh (peak tariff) | 1.0.1.8.1.255 |
Energy during peak hours |
| T2 kWh (off-peak) | 1.0.1.8.2.255 |
Energy during off-peak hours |
| Maximum demand | 1.0.1.6.0.255 |
Highest 15-min kW in period |
| MD timestamp | 1.0.1.6.0.255 attr 5 |
When MD occurred |
Event Log
Every significant occurrence inside the meter is recorded as a timestamped event. The event log is another Profile Generic object, capturing event code and timestamp for each entry.
Power Events
| Event code | Meaning |
|---|---|
| Power ON | Supply restored |
| Power OFF | Supply interrupted |
| Voltage sag | Voltage below threshold |
| Voltage swell | Voltage above threshold |
| Current unbalance | Phase currents differ significantly |
Tamper Events
| Event code | Meaning |
|---|---|
| Cover open | Meter terminal cover removed |
| Neutral disturbance | Neutral wire tampered |
| Magnetic interference | Strong external magnet detected |
| Reverse current | Current flowing backwards |
| CT bypass | Phase current with no CT signal |
| Meter bypass | Full bypass of the meter detected |
Communication Events
| Event code | Meaning |
|---|---|
| Wrong password | Failed authentication attempt |
| Configuration changed | Parameters modified remotely |
| Firmware upgrade | OTA firmware update applied |
| Key change | Encryption key rotated |
Putting It Together
Key Takeaway
Load profiles are the richest data a smart meter produces — they enable disaggregated billing, grid planning, and loss detection. Event logs are the audit trail — critical for fraud investigation and tamper evidence. Billing registers are the final word for revenue. In any AMI deployment, all three must be collected reliably.