Dear All,

We plan to use WAC routers for inter FCS Communications over different platforms.

WAC router intra domain allow time synchronization with accuracy less than 25ms (which is inline with our client specifications). But inter different Centum VP domains, the accuracy is at least 5s which cannot be acceptable by our client.

There is Safety PLC (Triconex - Tricon) on Domain 2 and our Time SNTP is belong Domain 1. I have 2 FCS in Domain 2. If i use the SNTP located in domain 1, i will synchronize with 5s of accuracy. Tricon is synchronized with the SNTP and i want to know if i can use a pulse generated each day at 11:00PM by my Tricon to set the time of my FCS belong domain 2? If yes, which function can i use in my control drawing?

 

Hi cedson,

I am sorry but I don't completely understand your problem. I will try to answer it as best I can.

Set a flag in the TRICON at 23:00:00 - let's call it TIMEFLAG.
Transfer the flag to the DCS using either hardwire or serial link.

In your FCS set up a %RQ request message from the TIMEFLAG (use a logic chart or sequence table).

In your HIS ENG use the %RQ to trigger a batch command, lets call it TIMESET.bat

Check the lag between the setting and receiving your FLAG and factor this into your timesync - lets assume it is 2s

So your TIMESET.bat file should be stored in the "\CENTUMVP\program" folder, and be something like:
C:\CentumVP\NET\Tool\TMSET -h 23 -m 00 -s 02 (where the time is HH:MM:SS and the delay is always 2s)

This will ensure the DCS time is distributed to all HIS, FCS, BCVV, SIOS etc.

Alternately - use a script to read the ntp time into HIS ENG and then distribute the time as above.
This is pretty easily done with kix32 & nettime;<pre>
Batch File
net time \\DOMAIN_SERVER /set /y

kix32 script
"C:\CentumVP\NET\Tool\TMSET -h " + left(@time,2) + " -m " + substr(@time,4,2) + " -s " + right(@time,2)</pre>
Cheers,
PB

 

Hi cedson,

In my opinion, provide Domain 2 with local SNTP Server(s). Retain the existing SNTP Server(s) for Domain 1 local use.

Notes:

There are a variety of ways of getting a time sync.
This approach is reliant on the SNTP Servers maintaining sync with standard time.

Consider refinements and fallbacks to mitigate failure modes. To at least maintain relative time consistency between the Tricon and the Domain 2 FCS.

Kind Regards,
Flash