How to configure the Time Synchronization with MM
We have a system that consists of the following:
- DCS Controller:172.16.84.XXX
- ESD Controller:172.16.84.XXX
- ESD-DCS Connectivity: 172.16.84.XXX
- RTU Controllers:172.16.80.XXX
- RTU Connectivity:172.16.80.XXX
I plan to implement the following; The DCS controller shall be the CNCP master with the ESD controller the CNCP slave. The DCS will also update the connectivity server which will then update the client server network.
The DCS will also configure the RTU controllers via MMS which should configure its connectivity servers; which will in turn update its client server network.
Now after reading the configuration document, i understand that my DCS controller should be considered as primary clock master (1 with No Sync), while my ESD should be (0 with CNCP) and i have to start the time service in my connectivity ESD-DCS.
Please confirm how will we configure the settings in the attached snapshot? For connectivity, Aspect Server and other Cleints?
Also how will we configure the time update for RTU via MMS and how will we make the respective connectivity server its slave?
Time synchronization is quite simple
1) Study how each protocol (CNCP, AfwTime, W32Time, etc) works, is setup and fault traced. Most is described in the network user's guide but additional information can be found on Google, AKS, etc.
2) System 800xA can not synchronize itself, nor figure out how to do it. Multiple different and valid methods exist and there is no "one size fits all". I sincerely recommend to paint a map of all networks and then mark where time "is born" and how and where it is connected.
3) Never configure a node to slave to more than one protocol at the same time. Its perfectly OK to act as master for one or more protocols at the same time, even in conjunction with being slave to something, but don't configure "double slaving".
Back to your question.
CNCP only works within the same subnet, so a CNCP master on the 172.16.84.0 subnet can not synchronize a CNCP slave on e.g. 172.16.80.0 subnet.
If the number of controllers are more than a few I suggest to setup a CNCP master (on each subnetwork).
AfwTime servers shall be located in one (1) of the connectivity server pairs, i.e. either .80 OR .84 - not both. If the AC800 Time Adaptor is installed (its it by default) the AfwTime service will pick up the CNCP time and relay it to all 800xA servers and clients.
Don't forget to use Win32Time to have the domain controllers to slave to some suitable SNTP server. I recommend starting W32Time in SERVER MODE (not client mode) in the AfwTime server nodes so that any node of interest can turn there for time.
The CNCP masters can simultaneously act as SNTP slaves (i.e. pick up adjusted time from an external source, e.g. the same connectivity server the domain controller is slaving to).
You must decide whether an AC800 shall act as time reference (i.e. use its internal oscillator) or use an external time reference (a GPS clock or an external computer, etc)
Since you have two control networks, one of them should slave to the other (or both slave to some external common time source). AfwTime will only be able to synchronize with one of the subnetworks, not both.
If external time reference is used (e.g. GPS) prepare for a loss of it. E.g. don't let every machine slave to the GPS individually, i.e. "star coupling". It might be better to let one node read the external reference (e.g. the domain controller) and then let all other nodes in the xA system slave to that clock. A domain controller with RNRP installed and enabled will be reachable by all AC800 CPUs.