VaiNet protocol and VaiNet devices are designed for power-efficient operation. To save energy and reduce signal overlap, VaiNet network transfers data at set intervals. This may be apparent to the user as longer data transfer times before the data is available in the viewLinc Enterprise Server.
Intermittent radio connections
Access points take turns communicating in a 2-minute cycle, and connected data loggers send their measurement data to their connected access point every 4 minutes. This introduces the following scenarios:
- Data loggers that are not currently connected (new devices, or devices that have fallen out of radio contact) scan for available access points for a complete cycle before they can decide what is the optimal access point for them. Connection attempts typically take at least a couple of minutes. Additionally, some joining scenarios may take multiple attempts. For example, when filling a single access point up to its full capacity of 32 data loggers, it may take an hour for the last data logger to successfully connect to the access point.
- Access points request missing data and issue management commands to data loggers within their communication window. Transferring a full month's worth of measurement data from 32 data loggers using 1 access point takes several hours.
Data logger scanning interval
Scanning for available access points consumes power. To prevent repeated scanning from draining their batteries, RFL100 data loggers that are not connected to an external power supply shut down their radio temporarily if they cannot connect to an access point. They will resume scanning after a waiting interval that gets progressively longer if they keep failing to find an access point. The maximum interval is 8 hours and 30 minutes.
This means that when access points become available after an outage, it may take several hours for data loggers to discover them. This is why you should always keep your access points powered up, and why you should start your network installation by installing the viewLinc Enterprise Server and access points first.
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You can manually wake up the radio of an RFL100 data logger by pressing its Info button. The button is located next to the service port under the silicone plug. |