Frequently Asked Questions

The ORN-TWM-LW868 module is installed on the water meter. Water flows through the water meter (the mirror rotates). Uplink 0x12 shows a zero counter value (it seems the ORN-TWM-LW868 module does not count the mirror rotations). Please explain what could be the reason for such behavior of the ORN-TWM-LW868 module?

Answer:
Before switching to counting mode, the ORN-TWM-LW868 module must successfully complete the calibration process. During calibration, thresholds are calculated (the signal range and the lower and upper levels are determined), and limits are set. The type of the reflective disk of the water meter is also identified. After completing the calibration, the radio modem switches to counting mode.

If the ORN-TWM-LW868 module is activated by water flow (a continuous flow of about 10 liters) through the water meter, calibration is performed automatically, and the module starts counting the mirror rotations correctly. However, if the module is activated using a magnet, after activation, a continuous water flow of about 10 liters is required for calibration.

In case the ORN-TWM-LW868 module is activated but the counter status remains zero, it is necessary to ensure a continuous water flow of about 10 liters. During this process, the module will perform calibration and start counting the mirror rotations correctly.

After completing the calibration, a service packet uplink 0x08 is automatically sent with parameters, including the type of the reflective disk.
```
781B30080800FA0709097E07E406D3078806058E
```
```
    {
        "0": 27,
        "1.4": 1,
        "1.5": 1,
        "2.8.0": 1,
        "2.8.1.0.8.0": 0,
        "2.8.1.0.8.0.0": 2042,
        "2.8.1.0.8.0.1": 1764,
        "2.8.1.0.8.1.0": 2313,
        "2.8.1.0.8.1.1": 2003,
        "2.8.1.0.8.2.0": 1918,
        "2.8.1.0.8.2.1": 1672,
        "2.8.1.0.8.3.1": 1,
        "2.8.1.0.8.3.7": 1,
        "2.8.1.0.8.4": 83,
        "description": {
            "0": "Sequence number",
            "1.4": "Tamper sensor status",
            "1.5": "Device time needs updating",
            "2": "Payload",
            "2.8": "Service data",
            "2.8.0": "Number of service payloads",
            "2.8.1.0": "Service #0",
            "2.8.1.0.8": "Calibration data",
            "2.8.1.0.8.0": {
                "0": "Device type - Apator"
            },
            "2.8.1.0.8.0.0": "Upper range channel #1",
            "2.8.1.0.8.0.1": "Lower range channel #1",
            "2.8.1.0.8.1.0": "Upper range channel #2",
            "2.8.1.0.8.1.1": "Lower range channel #2",
            "2.8.1.0.8.2.0": "Upper range channel #3",
            "2.8.1.0.8.2.1": "Lower range channel #3",
            "2.8.1.0.8.3.1": "Disk type- 180 degrees(flag)",
            "2.8.1.0.8.3.7": "Calibration was finished(flag)",
            "2.8.1.0.8.4": "Illumination value at the end of calibration (RAW ADC)"
        }
    }
```
To perform recalibration, the radio modem must be removed from the water meter for more than 3 seconds. In this case, an alarm event packet is generated, and the calibration process is restarted.

It is also possible to perform a forced calibration by sending a command via LoRaWAN Downlink to fport 2 or using the lora_dl command through the EasyTool tool for forced calibration:
```
78000000010D
```
Afterward, it is necessary to create a continuous water flow of about 10 liters, during which calibration will be performed, and the module will start counting the mirror rotations correctly.