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| Joined: | Sunday Jan 21st, 2007 |
| Location: | South Africa |
| Posts: | 598 |
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The PAC is a Cbus P2 time device and updates the devices, and Comfort, every 70 minutes. Native Comfort, without an Eth03 or Eth03 with SNTP disabled, should not send time updates more frequent than this, I think the standard in Cbus for a P3 time device is 150 minutes. Be that as it may, with an Enabled Eth03 it then changes from a P3 to a P1 time device which should send time updates back to Cbus between 30 and 70 minutes. This will override the PAC (P2) time device and we (Comfort) will not receive any updates as it yields control to Comfort (or the higher priority time device).
Now, if you don't have an Eth03 your Comfort is a P3 and Cbus is a P2 time device and Cbus will update Comfort every 70 minutes. This change is logged in the Comfort Event Log every single time. Here is where I propose that the event ONLY be logged IF the time change is greater than 4s as is the case with the Eth03. Cbus still updates every 70 minutes but it's not logged unless the time deviation is greater than 4s.
I like the Cbus time protocol, it's clear and simple. Three layers of priorities and they yield time to the 'better' source. With the Eth03's Max update time being 60 minutes it conforms perfectly to this standard. Relaxing that standard might make Cbus the Master again and it is only a P2 device. I would want the most accurate clock, the Eth03 in this case, be the Master. With both the Eth03 and Cbus updating time it could cause issues. I assume KNX, and other vendors, have a similar protocol.
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