Time Synchronization via AS

Hi, I'm using PCS7 V8.1 Sp1. We are having plant architecture of 1 OS server, 1 ES & 2 OS client using simatic s7-410-5H CPU. 

Is it possible to have time master configuration in AS in such a way that when receiving a digital input = '1', CPUs set time of day to 12:00pm, and synchronize all PC station to 12:00pm as well? Currently i have successfully program the CPU set time of day to 12:00pm when received '1' in DI, but I don't work it is workable to configure the CPU as time master?

Thanks Oreca for your reply.

I've gone through the manual but mostly their time synchronization are from either OS or external clock devices to the AS CPU, which mean CPU are time slave, it pass the time message to field bus to synchronize field bus devices. I can't find any example nor any guide to configure what i want.

Hi CKO,

for sure you can have the AS to be time master. But I would not recommend this. The time of the AS is the worst time you can get and will differ from real time by many seconds a day. So you can not trust the time of the AS.

Best is to follow the instructions in the already mentioned manual, OS time is much more accurate. Siclock is the best choice for absolutely perfect accuracy of time.

Regards
Myst

Hi Myst, i absolutely agree your comments, but in this case the system actually is IMCS, the time diff still in tolerance, in addition PCS will send DI to IMCS everyday to sync the time of day, so it shouldn't be a problem. 

In fact, i have successfully configure the PLC as time master now, it has been tested fews day is working fine now. 

Thanks for all helps.