Description
This article will describe how to check the problem when EM300-CL detects and reports the error full status of containers.
Checklist
Step 1: Check whether the test container is made of non-metal material. It is recommended to use plastic, glass, acrylic and other materials with a thickness of no more than 3mm.
Step 2: Check that the electrodes are installed correctly and attach the detection electrode sheet to the wall of the container seamlessly, aligning it with the bottom of the container to detect the liquid capacity. As shown in the following figure:
Note that the foam side should be face out:
Step 3: Check if the EM300-CL full liquid calibration procedure is correct.
1. Fill the container with liquid and calibrate using the Toolbox tool or downlink command.
NFC calibration via ToolBox App:
Downlink calibration: this should ensure EM300-CL has been added to any LoRaWAN network server or embedded network server of Milesight gateway to join the network.
Take Milesight gateway as example to send the calibration command: ff62ff
If the device receive this command and complete the calibration, it will return message: fe62ff.
2. Adjust the status detection interval of EM300-CL to 1 minute via ToolBox App or downlink command in order to get detection result quickly.
3. Slowly drain the liquid according to the following figure, until the liquid level is at the lower side of the electrode sheet. After the liquid level is stable (about 2-3 minutes), check if the EM300-CL will report a liquid empty alarm.
Note: it is not suggested to use that too thick liquid, since it is easy to lead to false detection if the slowly poured process liquid hangs on the wall of the container with electrodes.
Step 4: If EM300-CL still reports full liquid at the ④ state after operating above steps, the capacitor decision value needs to be adjusted.
EM300-CL detection principle:
(1) The electrode detection sheet is consist of two electrode plates. When the liquid is full and users complete the full liquid calibration, EM300-CL will record full liquid standard values: C1, C2 and △C.
C1=capacitor value of plate 1
C2=capacitor value of plate 2
△C=|C1-C2|
(2) When EM300-CL detects the liquid status periodically, it will record the capacitor values C1’, C2’ and △C’=|C1’-C2’|.
(3) if |△C-△C '| ≥120, EM300-CL will detect the liquid status as empty.
We can send downlink commands to enquire and reduce the value |△C-△C'| to adjust the sensitivity to ensure accurate result.
Note that this value can not be adjusted too low, otherwise EM300-CL will be too sensitive leading to misjudgment. After adjustment, please do not change the liquid type, otherwise it is possible to adjust the value again.
Adjust Example:
1. Ensure EM300-CL has been added to any LoRaWAN network server or embedded network server of Milesight gateway to join the network.
2. Adjust the reporting interval of EM300-CL to 1 minute via ToolBox App or downlink command in order to receive downlink command quickly.
3. Fill the container with liquid, then complete full liquid calibration as Step 3.
4. Slowly drain the liquid until the liquid level is in the middle of the electrode sheet (between not sure and empty location). After the liquid level is stable (about 2-3 minutes), check if the EM300-CL reports the status to network server.
5. Enquire and compare the capacitor sensitivity values.
Method 1: enquire via ToolBox App
(1) Open the debug mode of ToolBox App: How to Use Debug Mode of ToolBox App.
(2) Click Read to get EM300-CL device status, then go to debug menu and select Log tab to find the capacitor values from latest log.
Take above picture as example,
C1=5970
C2=5911
△C=58
C1’=5945
C2’=5855
△C’=89
The sensitivity value is |58-89|=31
Method 2: enquire via downlink command
(1) Send command ffbe00 to check the full calibration value.
Reply result：febe00 6916 4717 dd00
C1: 6916→1669(Hex)=5737(Decimal)
C2: 4717→1747(Hex)=5959(Decimal)
△C: dd00→00dd (Hex)=221(Decimal)
(2) Send command ffbe01 to get acquisition values when the liquid level is in the middle of the electrode sheet.
Reply result：febe01 ac15 eb16 3f01
C1’: ac15→15ac(Hex)=5730(Decimal)
C2’: eb16→16eb(Hex)=5948(Decimal)
△C’: 3f01→013f(Hex)=319(Decimal)
The sensitivity value is |319-221|=98
6. Send downlink command to adjust the sensitivity value.
Adjust to 80: ffbf01 5000 3200 9600 3200
(5000→0050(Hex)=80(Decimal))
Send command ffbe02 to confirm whether the modification is successful.
7. If it still doesn't work, try to adjust to lower values.
Adjust to 70: ffbf01 4600 3200 9600 3200
Adjust to 60: ffbf01 3C00 3200 9600 3200
8. If above settings take effect, adjust the reporting interval and status detection interval of EM300-CL back to large values via ToolBox App or downlink commands to save battery life.
Step 5: If above steps still do not work properly, please send the photo information and data of the liquid level during the test to Milesight Technical Support for analysis.
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