Type identification between datapoint of type float and float with timestamp

rajkumar.krishnan · Post by **rajkumar.krishnan** » Mon Jul 14, 2014 3:22 pm

Hello ALL,

I have a query how to identify the data point with type float and float with timestamp. When i checked with dpElementType for both it returnahjs same value 22.

Is there any other way to identy the difference.

Thanks in advance.

Regards,
Raj

fmulder · Post by **fmulder** » Mon Jul 14, 2014 3:50 pm

There is no type 'float with timestamp' Any dp element in WinCC OA (type int, bool, float, string, dyn_string, etc..) has a timestamp (and a quality, and a manager number, and some userbits and much more...). You might be talking about a driver adress where you might select a float with timestamp.

Some drivers (or actually some devices) will allow to read a value with a timestamp. This generally means that the PLC sends a value along with a timestamp. The specification 'float with timestamp' would mean that the driver accepts the timestamp as specified by the PLC.

Normally, there can be 2 source for the timestamp:

1) The receiver sets the timestamp. This could mean : a driver receiving a value, a UI setting a value.
2) The PLC sends a value with a timestamp

Hope this helps

Good luck

Frenk

rajkumar.krishnan · Post by **rajkumar.krishnan** » Tue Jul 15, 2014 1:15 pm

Thank you ...

rajkumar.krishnan · Post by **rajkumar.krishnan** » Thu Jul 17, 2014 6:31 am

Dear Frenk,

I have another query regarding the value with timestamp,

Consider,

1. I have a datapoint whose driver address is configured as float with time stamp.
2. Values are polled continuosly
3. Now i change the value of this datapoint with some value of type uint through control script.
4. Once i change the value through control script the polling stops abruptly even though modbus driver is running.
5. Now the device is polling other values without any issues but the value configured as float with time stamp is stopped.

What we found out even though address active is true,
I set the value to false and make it true immediately the teh datapoint is started polling again.

Could you please tell if there is any solution for this issue.

Regards,
Raj

leoknipp · Post by **leoknipp** » Fri Jul 18, 2014 4:54 pm

Hello,

maybe this issue is related to some smoothing functionality in the driver.
If the value is changed in WinCC OA the driver does not get an update. The smoothing functionality in the driver is always using the values received from the PLC and compares them with the values send to the event-manager.

How did you notice that polling is stopped for a single address/dp-element?
Have you activated debug-levels at the driver to get detailed information?

If you need furthier information how to debug this situation please get in contact with the ETM support team.

Best Regards
Leopold Knipp
Senior Support Specialist

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