800xA Time synchronization
I have a question regarding the time synch (800xA v5.1).
So, as in scheme in attachment 1, I have:
- 3 operator workstations on redundant client/server network
- 2 (redundant) domain/aspect/connectivity servers
- 2 AC800M HI controllers on redundant control network
- 3 AC800M controllers on redundant control network
I'm trying to find the best solution for time synchronization scheme (as I have read in manual).
So what do you think about this scheme:
GPS receiver Meinberg M400 connected to the control network would be an NTP server for two AC800M's (CNCP primary master and CNCP secondary master), and the three other controllers would be CNCP slaves. DS/AS/CS 01/02 would receive time by CNCP, and OS 01/02/03 would receive time by afwtime.
In manual I've seen that when a GPS Receiver/Server is used, it is proposed that Domain Controller fetches the time via SNTP (attachment 2), but in my case Domain Controller is implemented in DS/AS/CS, so I think that it would be better that DS/AD/CS receives time by CNCP.
Thanks in advance!
Voted best answer
I see no problems with the suggested configuration!
Just be sure to verify that AfwTime receive the CNCP pulses (as there has been issues when the AC800MTimeAdaptor.dll has not been installed/registered on disk even though it was requested so) e.g. by stopping AfwTime and change the time slightly and then turn on AfwTime and verify that all computers land on exactly the same second as the DateTime function block of AC 800M displays.
Remember that CNCP pulses only travel within the same subnet; if you where to move the HI-controllers to a separate subnet (RNRP Area) you would have to get them synched by SNTP.
Last; CNCP derive settings from RNRP. No RNRP = no CNCP. Use Clock Sync Tool of CBM to verify clock status; the controller log does also show SNTP messages, e.g. if the external reference is lost or deliver unreliable time.