Win7 as a SNTP time server for AC800M
Is it possible to use PC with Win7 for a time server for AC800M by using of SNTP?
We have AC800M OPC Server installed on the PC, but third party SCADA, connected to the AC800M. The PC is time synchronized by Internet (windows time service), and we need the AC800M to have the same system time as the PC.
When I set AC800M as a time server with SNTP, it seems it sets the time of Windows, which we don't need. The PC has an address 172.16.4.40 and AC800M is 172.16.4.1
The settings of AC800M are the following:
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Yes, of course!
The AC 800M can slave to any SNTP source it can reach via known routes (hardcoded with IPConfig.exe or told dynamically by RNRP) or via its own default gateway, even a Microsoft Windows PC clock (a.k.a. Win32Time service) as long as it is advertising as a reliable source.
UDP port 123 need to be open along the route.
Concerning reliability, please read about "announceflags" in the 800xA Network User's Guide, it contains examples of how this configuration is done. No 800xA software required!
On the other hand, most PCs have poor time quality (MS Windows is not really a RTOS). If the appointed clock or its external reference is not "smoothly synced & running" the AC 800M SNTP slave will warn about time jitter. Expect these warnings to flood the controller log if you use a PC as reference.
Time jitter is typically no issue for a slow acting application, but for a fast acting application with SOE IO it could be a big problem.
In the end, pull the controller log - it should say "Valid time server found. Stratum = x" where x=0 is bad, x=1 the reference itself (e.g. an atomic clock) and 2, 3, 4, 5+ is the number of jumps away from the reference (each jump makes the time have more jitter).
Time deviation should typically not exceed 10 ms to provide a reliable sequence of events. That's why you want the AC 800M to sync the network, w/o using an external clock. A Windows PC has an accuracy of 1-2 sec. so normally not recommended for time sync.
This is my idea how it could work:
You can configure your Windows PC, connected to the Internet, as SNTP server. Take care of accuracy (ext. clock ?). Then sync through the firewall an 800xA node in the C/S network, preferable the Domain Controller, which then syncs all 800xA nodes via Afw time service, and then the Connectivity Server syncs the AC 800M controller in the control network via CNCP. CS is CNCP Master, AC 800M is CNCP slave.
Q:Is it possible to use PC with Win7 for a time server for AC800M by using of SNTP?
Ans: yes, You can use but it should not be part of the xA environment since 800xA uses its afw time service to sync (Ac800M acts as SNTP client/CNCP Master->CS will acts CNCP slaves and afw time server to xA nodes).
Let domain take time directly from controller via RNRP router (CS).
Q:When I set AC800M as a time server with SNTP, it seems it sets the time of Windows, which we don't need. The PC has an address 172.16.4.40 and AC800M is 172.16.4.1
Ans:Yes, Controller acts as both SNTP client when use the SNTP address and SNTP server for the other windows environment to get time pulse.
Inject some more info..system configuration with domain/workgroup,method followed for time sync.
The configuration is very simple, no any 800xA or domain/s installed on the PC. It is not required ms precision, I need only to have the same time in the PC and AC800M controller. The solution with external GPS time server is clear for me, I used it in other bigger proects.
The PC is Win7 based 64-bit, with AC800M OPC Server and SCADA OPC Client (not ABB), Control Builder M, ver. 5.1. We have only 1 pc AC800M controller, connected to this PC.
Windows is synchronized with Internet time, standard service, and I made modification in registry this to be executed each 1 hour (not standard 1 week). That is enough for our application. So now I need the PC time to be set to AC800M controller in some reasonable time period (PC time -> AC800M time), excluding the oposite action (AC800M time -> PC time)