Avatar

Please consider registering
guest

sp_LogInOut Log In sp_Registration Register

Register | Lost password?
sp_Search Search
Advanced Search
Advanced Search

— Forum Scope —




— Match —





— Forum Options —





Minimum search word length is 3 characters - maximum search word length is 84 characters

sp_Search Search
Go to Bottom
No permission to create posts
sp_Feed Topic RSS sp_TopicIcon
DataChange Notification when value doesn't change
May 14, 2019
19:20, EEST
Avatar
kkettinger
New Member
Members
Forum Posts: 2
Member Since:
April 29, 2019
sp_UserOfflineSmall Offline
Go to Top
1sp_Permalink sp_Print

Hello,

is it normal to not receive DataChange notifications when the same value is written to the server?
When i’m writing the same value to a variable to the server, the source/server timestamp doesn’t update
and we can’t recgonize that the value was written. We don’t know if the client is still alive.

Is this expected behaviour?

I couldn’t find if that is normal, so any clarification on this would be of great help.
Thank you!

Best regards,
Kevin

May 15, 2019
9:55, EEST
Avatar
Bjarne Boström
Moderator
Moderators
Forum Posts: 1042
Member Since:
April 3, 2012
sp_UserOfflineSmall Offline
Go to Top
2sp_Permalink sp_Print

Hi,

That is the default behaviour of OPC UA, unless you have set a DataChangeFilter with DataChangeTrigger STATUS_VALUE_TIMESTAMP (1.04 Part 4 section 7.12.2). By default the SDK’s MonitoredDataItems do not set a filter, therefore you will get only “STATUS_VALUE” changes, i.e. only if the StatusCode or the actual Value changes.

You can set it via MonitoredDataItem.setDataChangeFilter(DataChangeFilter).

DataChangeFilter filter = new DataChangeFilter();
filter.setTrigger(DataChangeTrigger.StatusValueTimestamp);
filter.setDeadbandType(UnsignedInteger.valueOf(DeadbandType.None.getValue()));
May 15, 2019
11:24, EEST
Avatar
kkettinger
New Member
Members
Forum Posts: 2
Member Since:
April 29, 2019
sp_UserOfflineSmall Offline
Go to Top
3sp_Permalink sp_Print

Thanks Bjarne, that helps me!

No permission to create posts
sp_Feed All RSS
Go to top
Forum Timezone: Europe/Helsinki

Most Users Ever Online: 1919

Currently Online:
24 Guest(s)

Currently Browsing this Page:
1 Guest(s)

Top Posters:

Heikki Tahvanainen: 402

hbrackel: 144

rocket science: 90

pramanj: 86

Francesco Zambon: 83

Ibrahim: 78

Sabari: 62

kapsl: 57

gjevremovic: 49

Xavier: 43

Member Stats:

Guest Posters: 0

Members: 780

Moderators: 8

Admins: 1

Forum Stats:

Groups: 3

Forums: 15

Topics: 1543

Posts: 6509

Newest Members:

anglea06o05589, matsa, Jameshax, Jeffreyfledy, lilliefalconer, Olpsom, shastaappleton, hildred39i, Adam, tammara49z

Moderators: Jouni Aro: 1029, Pyry: 1, Petri: 0, Bjarne Boström: 1042, Jimmy Ni: 26, Matti Siponen: 353, Lusetti: 0, Elias: 0

Administrators: admin: 1