Help Understanding How to Feed Data to openHist

I have a SEL3530-4 RTAC that I am trying to use to send MODBUS data to openHistorian. Right now I’m playing with it on my desktop and if I can get it working I plan on installing on a linux server later on.

I’m having trouble understanding how to set things up so information is being recorded into the openHistorian. I have the RTAC configured to send a single analog value to the OH. I picked the neutral unbalance current in a double wye filter bank as a sample tag.

In the web interface if I open up ‘Devices’ and click ‘RTAC’ and then click ‘Connect’ I can see the tag with the correct analog value displayed. However, if I navigate away from this page the connection to the RTAC closes and data transfer between the RTAC and OH stops. Further, if I ‘Monitoring’ -> ‘Trend / Export’ no points are available for selection and trending.

I can’t help but shake the feeling I’m missing some basic configuration step, but I can’t find much detail in the help section.

It may be necessary to assign to the device to the “PPA” primary archive in order to get points saving into the historian. You will need to do this from the openHistorian Manager (not web based, but application), navigate to the device details and set the historian to “PPA”.

Ritchie,

If I set the device historian and the point tag historian both to PPA in the openHistorian Manager, I can see the point in the ‘Trend / Export’ select points area of the web interface. So that works! However, I cannot get the trend to display any data. It is always a blank area outlined in black after I hit the ‘Trend’ button. I have played with the trend options to verify it was not a issue with me picking times that didn’t exist or anything.

If I try to display the data in the openHistorian Manager I can drill through the drop down list to the point tag I want to see, but it does not allow me to select it. I can’t check the checkbox that sits next to the tag.

The connection issue also still persists. If I navigate away from the web interfaces ‘Modbus Configuration Map Builder’ page OH will drop the connection with the RTAC instantly. In order for the two to communicate again I have to go back to this page and hit the ‘Connect’ button.

Try re-initializing the adapter and see what happens - I suggest doing this from the console to be able see what happens / any messages / etc.

You can do this by issuing the command initialize RTAC

When I try to open the console I see the following that just repeats.

Connecting to tcp://localhost:8510...

Connected to tcp://localhost:8510:

              Client state: Connected
           Connection time: less than 1 second
            Receive buffer: 8192
        Transport protocol: Tcp
        Text encoding used: US-ASCII

Remote client connected - Username from Computer-Name.

[RTAC] Attempting connection...

[RTAC] Connection attempt failed: Object reference not set to an instance of an
object.

[RTAC] Device disconnected.

[RTAC] Disconnected.

[RTAC] Attempting connection...

[RTAC] Connection attempt failed: Object reference not set to an instance of an
object.

[RTAC] Device disconnected.

[RTAC] Disconnected.

Well - there’s the issue :slight_smile: What version of the openHistorian are you using?

Server: 2.5.6.0
Manager: 2.5.6.0

Let’s check the ErrorLog.txt - see if it provides a little more detail.

Its a big file, but the below seems to be a common theme.

---- Stack Trace ----

[6/27/2018 2:44:19 PM] (Inner Exception)
Date and Time:         6/27/2018 2:44:19 PM
Machine Name:          Computer-Name
Machine IP:            fe80::ac90:a8de:c3b5:2196%26
Machine OS:            Microsoft Windows NT 6.1.7601 Service Pack 1

Application Domain:    openHistorian.exe
Assembly Codebase:     C:/Program Files/openHistorian/openHistorian.exe
Assembly Full Name:    openHistorian, Version=2.5.6.0, Culture=neutral, PublicKeyToken=null
Assembly Version:      2.5.6.0
Assembly Build Date:   6/1/2018 12:22:34 AM
.Net Runtime Version:  4.0.30319.42000

Exception Source:      ModbusAdapters
Exception Type:        System.NullReferenceException
Exception Message:     Object reference not set to an instance of an object.
Exception Target Site: AttemptConnection

---- Stack Trace ----
   ModbusAdapters.ModbusPoller.AttemptConnection()
       openHistorian.exe: N 00617
   GSF.TimeSeries.Adapters.InputAdapterBase.AttemptConnectionOperation()
       openHistorian.exe: N 00250


(Outer Exception)
Date and Time:         6/27/2018 2:44:19 PM
Machine Name:          Computer-Name
Machine IP:            fe80::ac90:a8de:c3b5:2196%26
Machine OS:            Microsoft Windows NT 6.1.7601 Service Pack 1

Application Domain:    openHistorian.exe
Assembly Codebase:     C:/Program Files/openHistorian/openHistorian.exe
Assembly Full Name:    openHistorian, Version=2.5.6.0, Culture=neutral, PublicKeyToken=null
Assembly Version:      2.5.6.0
Assembly Build Date:   6/1/2018 12:22:34 AM
.Net Runtime Version:  4.0.30319.42000

Exception Source:      
Exception Type:        System.InvalidOperationException
Exception Message:     Connection attempt failed: Object reference not set to an instance of an object.

Everything on my end is utilizing IPv4, so I’m not sure why its listing my machine IP in IPv6.

Let’s try “re-saving” the Modbus device - just to make sure the connection string is good, i.e., press the Save Device button on the web page again. The issue is not obvious to me here,

Still no joy.

Connection String:
hostName=172.17.20.90; port=502; frameFormat=TCP; transport=TCP; unitID=255; pollingRate=2000; interSequenceGroupPollDelay=250; sequenceCount=1; sequence0={sequenceType=Read; groupCount=1; groupType0=IR; groupStartAddress0=0; groupPointCount0=1}

Just to double-check, you do have an NModbus4.dll in the installation folder?

Yes, I have a C:\Program Files\openHistorian\NModbus4.dll that is 74KB.

If it matters, I am online with the RTAC watching the ‘Offline’ and ‘Message_Sent_Count’ indicators to determine when OH is connected. It is as soon as I navigate off the page it drops the connection. By that I mean, if I click any other web button like ‘Home’ or ‘Devices’ the connection will drop.

I can however switch tabs and the connection is unaffected.

oh_offline

Yeah - this is very weird - Stephen and I are staring at code, there is almost no possible way (AFAICS) for a null exception to occur, except that is does.

Connecting from the web page uses the Modbus code just like the adapter does - so at least it’s good that the Modbus connection / DLL works.

If you right-click on the ModbusAdapters.dll - what does it show for version under the details tab?

I see a ModbusAdapters.dll version of 2.2.259.0 and a product version of 2.2.259-beta.

I really appreciate all the help! I’m about to duck out for the day and will get back to playing with it tomorrow. I have no issue trying things, screen shooting things, etc.

Edit: Also, I will restart the RTAC and my machine first thing in the morning to make sure everything is starting fresh.

We may have replicated your issue - we’ll leave a note with what we find…

So quick answer - the code as written will ignore sequence address starting at zero - not sure if that is correct behavior, but can you change register to 1? We will update the code to accept zero and/or better handle reporting the exception.