Those are the settings for COV timing and cyclical reading. Which bOS uses is controlled by the settings on BACnet objects. Some devices might not support COV and some support only a few slots. If that is the case, you can use cyclical reading, which sends read commands every x milliseconds (defined by Read Delay setting). It is recommended that you use COV if device supports it. Make sure you read the manual of the device carefully so the connection settings are set correctly.
- Subscription Time: This is a time in minutes and it defines for how long the COV subscription is valid. When defined time runs out, bOS will resubscribe. By BACnet standard, devices should support at least 8 hours long COV subscriptions. This is why the default value is 480 minutes. Some devices might not keep the 8 hours COV subscription. That is on you to figure out what works best for particular device and network.
- Read Delay: In case you are using cyclical reading, this is a delay in milliseconds between each read command. For example, if you have 10 objects to read and read delay is set to 250 ms, it will read each object every 2,5 seconds.
Customer support service by UserEcho