System: Small PCS 7 setup with 1x PCS 7 Box PC and 1x Automation Station (AS) 410H.

Network: PCS 7 Box PC has two NICs:

• (Terminal Bus): Connected to site domain; Windows time is synchronized correctly from site NTP.
• (Plant Bus): Connected to AS 410H / PN network.

Time concept: The PCS 7 Box PC is intended to act as an intermediate NTP/time source for the Plant Bus. (Windows W32Time configuration appears correct; PC shows correct time.)

AS/PLC settings:

• In CPU Set Time of Day, “Take from PG/PC” is enabled.
• The PN interface/PROFINET card is configured for time synchronization, with the Plant Bus IP of the PCS7 PC entered as the NTP/time source.
• Time zone selected:(GMT) Dublin, Edinburgh, Lisbon, London(system located in Ireland).
• UDT60/DB settings mention:B2L: S=0, T=2(DST conversion rules).

Symptom:

• PC time is correct.
• In PLC “Set Time of Day” window:PG/PC time is correct, butModule time and Local time are exactly +1 hour.
• WinCC alarms that originate from the PLC are also stamped +1 hour

Question:

• If I change the time zone from(GMT) Dublinto(GMT) Casablanca, Monrovia(UTC without daylight saving), would that remove the 1‑hour offset?
• If I download the time zone/hardware time settings to the PLC, will it wipe the code completely?

Hi,

For me the best way is to provide the AS with UTC time.
Please follow the manual, their a number of configurations possible:

SIMATIC PCS 7 Time Synchronization (V10.0)
https://support.industry.siemens.com/cs/ww/en/view/109973498

Br,
Cedric

Thank you Cedric. 

Which of the following should I use

(GMT) Casablanca, Monrovia or

(GMT) Dublin, Edinburg, Lisbon, London