Last Seen vs Last Log
How Clever Logger works
The logger measures and broadcasts the temperature every few seconds.
Last Seen
The gateway “hears” these broadcast temperatures but ignores most of them. But every now and then, it will update the logger’s “Last Seen” status to show that it is still receiving the readings.
Last Log
Every few minutes, the gateway will take the most recent temperature that it has heard and writes it to the log on the internet. The “Last Log” status is updated each time this happens.
If everything is going well...
If everything is going well, the Last Seen and Last Log statuses will be, at most, only a few minutes apart – as in the example above.
This means that the gateway is getting regular readings from the logger/s with no problem.
If things aren't working...
In this example, we can tell from the up-to-date Last Seen status that the logger is still broadcasting readings and the gateway is still hearing them.
So why is the log so far behind?
At some point (in this case, about 8 hours ago) , the logger has failed to get a reading through to the gateway. The gateway has paused the log at this point and attempted to send a message back to the logger requesting the missing data. That message has failed to get through, so the gateway is still waiting for the missing data before it updates the log.
What causes this?
The most common culprit is low signal strength. If the logger is only just getting the signal to the gateway, as we can see from the 15% signal strength in the illustration, then it is not going to take much to block a signal from getting through.
How do I fix it?
You can temporarily fix the problem by placing the logger next to the gateway for a few minutes. This will allow the gateway to successfully request the missing data. Once the log is up to date, you can place the logger back where it was.
The trouble with this is that the problem is likely to re-occur, since we haven’t improved the situation.
The long-term solution is to improve the signal strength between the logger and the gateway, usually by moving the gateway closer to the logger. It may help to connect the gateway to your wi-fi to achieve this. Or, if the gateway handles multiple loggers, you may need to buy an additional gateway.
In this example, both the Last Seen and Last Log statuses are out-of-date.
We can tell from this that the gateway is not receiving any readings from the gateway.
What causes this?
There can be a couple of reasons for this result.
- The gateway could be offline
- The logger could be too far away from the gateway
- The battery in the logger could be flat
How do I fix it?
To find out if the gateway is online, open the Clever Logger dashboard and check the gateway’s status.
To check if the logger’s battery is flat, look for the In Use light on the logger. If there is no light, then the battery is probably flat.