Implementing Time Synchronisation between DCS and PLCs


Thread Starter

Sushanta Saha

we have a requirement for Time synchronisation between DCS, PLC and all subsystems. We have combination of ABB Symphony DCS with August CS300 PLC, Honeywell TDC3000 DCS with Triconex Ver. 9 PLC, Yokogawa Centum CS3000 DCS with Triconex Ver. 8 PLC, Honeywell TDC3000 DCS and GE Mark-V GT control System.

Now what are the options available for implementing Time Synchronisation between the DCS and PLCs ? How do I do it ?

Every DCS has a windows platform interface. With this, you can have all your DCS/PLC systems on windows interface, have a GPS in place, configure all the servers (of all systems) to use this GPS as its time source.

Having mentioned GPS, there will be a big task of integrating all the DCS networks to one GPS, which would call for extensive networking/routing and firewall separations.

As for Honeywell DCS with Tricon SM, this can be achieved with an ESVT (Experion Server-TPS) as time source on LCN. This ESVT in turn must be configured to receive clock signals from GPS as it is on Windows 2008 server platform.

You must consult in house networking experts, as well as all the OEMs put together.

Good luck
Hi Sushanta,

GPS timesync was the gold standard 20years ago - specifically used for power grids to allow fault finding of events across multiple utilities consumers and suppliers. These days we use an NTP server (shareware versions are available if you like, our IT department maintains ours for the whole business), which synchronises from the internet.

The control system firewall picks up the time from the NTP server, which is then used internally within existing control system networks to set the time on DCS, PLC, ESD, Historians, and legacy Unix and older Windows boxes. These boxes/applications all provide a automated means/tools to set their own time - i.e.; Yokogawa have a command line tool C:\CentumVP\NET\Tool\TMSET which accepts a parsed time format.

It sounds like you have a fair old collection of boxes - so I imagine you'll be reading manuals for quite some time!

Regards, PB
Hi everyone,

We had the same problem of time synchronization between SIEMENS DCS (PCS7) for combine cycle plant, MarkV & Thoms control system only for GT.

SICLOCK is used to distribute timestamp to all PCS7 computers, all SIEMENS PLSs and all are well synchronized. Our problem was Mark V (DOS) and Thoms (Windows NT) were having different timestamp.

Then I used NTP to make time synchronization between (one of the) PCS7 client computer (Windows 2000) and the Thoms PC (Windows NT). Again I converted the Thoms computer as a Master (Time Server) for MarkV system. Now all the Cores even all <I> and <G> computers are following PCS7 time (GPS clock).

Deepak Goyal

Saha, which is your common device? Meaning, the one talking to all other devices. Use this device to generate master token and distribute. Once other devices receive the token, configure them to reset clock to pre defined time.

Problem comes, when there is no common / single master like multiple sites, in that case you might need take help of GPS and use that as master. Depending on how many isolated nodes you have, you would need as many GPS inputs.

Success as always in your configuration.........

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