That's an excellent question. As I explain in the video, there are two methods of getting this done. If you want to sync the HMI time, you need to add it into the global connections. However, it's easier to ignore that and base it off the PLC values. I find that this way, it's easier to migrate displays and the time will remain consistent with the PLC it's communicating with.
Hi Vlad! What happens if I want to do exactly the opposite: write the local time from HMI to PLC? Generally the HMI user has access to adjust the HMI local time but he does not access to do that in the PLC.
Fernando, you can certainly do that, but I would advise against it. A better solution, if you want to change the time from the HMI would be to set the PLC as the master and create logic which would display the PLC tags on the HMI and allow them to be changed. The reason for this is that PLCs have integrated sync functions which are usually implemented to synchronize time settings among PLCs. I've never seen an HMI be the master. Furthermore, in distributed systems, a server would hold the time.
@@SolisPLC Thank you for your answer. My equipment is a stand alone system, and for some reason, the time in the PLC is delayed 3 min weekly. Right now a screen already is configured with your proposed solution; the user enter the HOUR, MIN and SEC manually. I want to replace this option with a button to copy directly the system time of the HMI (3 tags) to the PLC (3 tags too).
Hi. I am curious why you did you not use Objects-> Advanced->Time and date. Is this connected to the Global connections if the PLC time tags are set in there also or does it take the time form the HMI when it is set when started up?
Trending is something that's done separately as you pointed out. I've been planning on covering it at some point, but never got to it. Panel view terminals have a special section to create trends. That being said, it's a bit more advanced than what's shown here. It's also not ideal with default settings (in my opinion).
A year ago I did something similar to this but I didn't put it global connection needless to say the alarms in the banner has a different time that the one in the main banner. Client was not happy.
