Clock data in TP177A

[PdL]

In WinCC Flexible compact I've added a date/time field in a screen. I have configured it to display system date/time. In the live screen in runs, but it does not seem to retain its value when the power is cycled, it always start with 01-01-2004 12:00:00 Do I need to load the time from the CPU ? I am using an S7-200 CPU226 so I guess I would need to set the time using the SET RTC function and point the date/time field in the TP177 to the output data of the function? Any help appreciated.

[JesperMP]

Hi PdL. The RTC in Siemens panels gets reset after a relatively short time. So syncronizing with the PLC is really important if you use the clock on the HMI (and who don't). Look here: http://support.automation.siemens.com/WW/view/en/26492257 edit: I assume that a TP177A moste closely resembles a TP170A or a TP177micro. If it is actually a Windows panel, then look here: http://support.automation.siemens.com/WW/view/en/26489261 Edited July 1, 2008 by JesperMP

[PdL]

Thanks Jesper, looks like that's exactly what I was looking for

[PdL]

I used the library download and suited it to my needs. It works great, however there is one problem. The area pointer aqcuisition cycle that updates the system time is set to 1 sec. However when there is an active alarm at startup, it logs the date/time as 01-01-2004 12:00:25. So probably the alarm processing is started before the first update of the area pointer. It seems to take 25 seconds from boot to start the alarm processing. Once the runtime screen shows, the time is correct. Is there any way to delay alarm processing until the first update of the area pointer? Mind that I have got a TP177A which cannot use scripting. It also comes short of a -imo fundamental- function like ability to log alarms in a history; any alternatives available?

[JesperMP]

Yes, TP277 ! :)The TP177A is a low-cost panel, so you have to accept a number of compromises. But I know that at least the TP/OP177B stores the alarms retentively (probably as long as the capacitor can keep them). So you can view them on the screen even after a power cycle. If the TP177A also suports this I do not know.

[PdL]

Probably the TP177A is one of the lucky ones It have found some functionality comparison charts amongst the various TP models, but neither say anything about logging. I guess I would just have to do without, hopefully my customer agrees

[JesperMP]

Alarm "archiving" and retentivity of the alarm buffer is not the same. Alarm archiving will store the alarms in a CSV file on a flash-card you insert in the panel. That means "permanent" as long as the ring-ordered alarm file(s) do not get overwritten. The retentivity means that the normal alarm view will display the buffered alarms (alarm history), even after a power cycle, but only for so long that the capacitor can keep the memory. And I do not know how long that is. Probably not for as long as a weekend. This functionality was added with the latest xx7 panels. But I am not sure if the TP177A has this feature. Just give it a try !