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quickopc-da to quickopc-ua conversion

21 Jul 2021 18:59 #10028 by support
Thank you - I see - yes, in the part that you have now posted, "DataSource = 2" does the right thing.

In OPC UA, to achieve roughly the same thing: Inside the UAReadArguments (which you are already creating), there is a ReadParameters property (of type UAReadParameters). And inside it, there is a MaximumAge property. And you need to set it to zero. That's it. I do not have the actually verified syntax in PowerBuilder for you, but I suppose you will be able to figure it out with this in hand. If not, let me know and we will together on that.

Best regards
The following user(s) said Thank You: spaxman

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21 Jul 2021 17:31 #10027 by spaxman
Sorry you are correct it was down on the next object level where I am specifying to device.
the easydaclient settings
opc_struc.item_list[ll_idx] = CREATE OLEObject
opc_struc.item_list[ll_idx].ServerDescriptor.ServerClass = g_opc_server
opc_struc.item_list[ll_idx].ItemDescriptor.ItemID = opc_struc.item_ids[ll_idx]
opc_struc.item_list[ll_idx].ReadParameters.DataSource = 2 // read to device
opc_struc.msg_opclabs_handles.Add(opc_struc.item_list[ll_idx]) // add to vector

the easyuaclient settings
opc_struc.item_list[ll_idx] = CREATE OLEObject
opc_struc.item_list[ll_idx].EndpointDescriptor.UrlString = gs_opc_ua_server
opc_struc.item_list[ll_idx].NodeDescriptor.NodeId.ExpandedText = ls_ns +opc_struc.item_ids[ll_idx]
opc_struc.msg_opclabs_handles.Add(opc_struc.item_list[ll_idx]) // add to vector

the read methods used are
valueResultList = g_opclabs.ReadItemValueList(opc_struc.msg_opclabs_handles)

valueResultList = g_opclabs.ReadList(g_msg100_send.msg_opclabs_handles)

everthing seems to be working but I need the easyuaclient to always get the data from the device like the ReadParameters.DataSource = 2 setting on the da client.

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21 Jul 2021 16:35 #10025 by support

the answer would be easier for me if you send me the piece(s) of code that constructs the arguments to the ReadList method (msg_opclabs_handles), because that's where the settings would go.

I should note that a) you might be confusing what "synchronous read" and "reading from device" are doing, and b) the settings you have listed for OPC DA actually do not assure reading from the device, they just assure sync read.

Best regards

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21 Jul 2021 16:14 #10024 by spaxman
I am new to opc-ua... I have been using the Easydaclient for about 2 years with good success. We now are migrating to a new OPC server (Ignition) that only supports opc-ua. I have modified my code (powerbuilder) to connect and use the easyUAclient. My question is I had many settings on the EasyDaclient that made sure I was do syncrounsu reads to the device. Below you can see my settings.

g_opclabs.Isolated = true
g_opclabs.InstanceParameters.Mode.AllowAsynchronousMethod = false // only do sync reds
g_opclabs.InstanceParameters.Mode.AllowSynchronousMethod= true
g_opclabs.InstanceParameters.Mode.DesiredMethod = 0
g_opclabs.InstanceParameters.UpdateRates.ReadAutomatic = -1 //System.Threading.Timeout.Infinite
g_opclabs.InstanceParameters.UpdateRates.WriteAutomatic = -1 //System.Threading.Timeout.Infinite
g_opclabs.InstanceParameters.HoldPeriods.TopicRead = 600000 //keep tags active for 10 MIN after each read
g_opclabs.InstanceParameters.HoldPeriods.TopicWrite = 600000 ////keep tags active for 10 MIN after each write

for the easyUAclient I only have isolated setting
g_opclabs.Isolated = true

I need to get the data from the device on every read. Is there a setting to make sure this is occurring.

I am using the g_opclabs.ReadList(g_msg100_send.msg_opclabs_handles) method and it is working. I just want to make sure I am always ( this is critical) getting the data from the device and not the server.


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