Help S7 date and time from TP177B

[JohnW]

Anyone know how to get the time and date from a TP177B? I have tried the settings in the Seimens help files but I cant get it to work. I want to send the date and time from the winCE system clock to a IM 151.

 

[PLucas]

John

I am not sure if you can do what you want to do, but if you have a look at this thread you will see an example program posted by RRobins that might help you

Paul

 

[JohnW]

Thanks Paul, the TP177 is different to the TP170 as it uses WinCE. I am talking to Siemens about it at the moment and will update later.

 

[JohnW]

Well it turns out that the TP177b doesn't have a hardware clock! So I have been wasting my time. I shall have to read the time the other way, which I can do. Siemens is sending me some code to change the PLC clock for daylight saving time.

 

[whtrader]

Hi JohnW,

I am having the same problem. Did you write some code on the plc and link to TP177? Please provide some example.

 

[JohnW]

Yes here is how to do it from Siemens

 

[JesperMP]

Hello John.

Previously you wrote "it turns out that the TP177b doesn't have a hardware clock".
But I think it does have (on my OP177Bs there is a clock). The guide you posted also describes how to transfer the panels system time to the CPU - meaning that there is a clock on the panel.

It is the TP170A (and maybe also TP177A) that doesnt have a clock.

What I do know is that the new panels dont have a battery, only a high performance capacitor. So if the panel is shut down for couple of weeks, the clock will be set back to 1994. Same as the S7-300 PLCs actually.
So if you do some syncronisations beween panel and S7-300 CPU, you should check for a suspicious date, like "1994" and prompt the operator to set the clock if necessary.

 

[JohnW]

Jesper,

OK I was a little innacurate there is a RTC but it is not battery backed and I have found that the units I have used the clock reset to 1994 on power up. So I just send the PLC time once a minute to ensure syncronisation. If the newer TP177bs have a capacitor then that is good but I cannot be bothered to test the TP time when it is easier to just synchronise routinely.

 

[JesperMP]

John, if your PLC is one of the newer S7-300's with MMC cards, then the clock in these also only have capacitor backup. According to someone's test (Roy I think to remember), the capacitor can hold up for a weeks time or so.
Thats why I suggest to check for "1994" and prompt the operator to set the time when necessary.

 

[JohnW]

John, if your PLC is one of the newer S7-300's with MMC cards, then the clock in these also only have capacitor backup. According to someone's test (Roy I think to remember), the capacitor can hold up for a weeks time or so.
Thats why I suggest to check for "1994" and prompt the operator to set the time when necessary.

It is in fact a IM151-7 but that is essentially a new type S7-300, I hadn't really considered the possibility of the PLC losing its time although I have included a facility for the operator to set the PLC time by first setting the system time on the TP177 and then sending that to the PLC. In practice the application is an unmanned sewage pumping station that is never shut down for more that a few hours at a time (and then very rarely). We had a power outage during the world cup caused by the electricty company re-organising supplies as a result of increased demand during the last England game! but that only lasted a few seconds.
The plant is monitored by a SCADA system via GPS so I could put in a "PLC clock fault" flag to SCADA.

The plant is fitted with a generator connection for long-term power failures.

 

[whtrader]

Yes here is how to do it from Siemens

Thanks JohnW for the reply. Unfortunately I am using S7 Micro Win and S7 200 PLC to TP177Micro. I found one guide below but still unable to get it working.
http://support.automation.siemens.com/GB/llisapi.dll?func=cslib.csinfo&objaction=csopen&objid=10832831&lang=en&siteid=cseus&aktprim=0&extranet=standard