eHMI not accessible

PLCnext Technology & PLCnext Controls
1

Dear all,

Recently I have encountered an issue with my eHMI application. Namely, I cannot access it neither via the PLCnext Engineer’s simulator (getting a black screen) or the browser (in both Edge and IE I get redirected to WBM). In the past I have managed to have my eHMI run on the controller and have already encountered a similar problem, that was solved by resetting the controller to factory defaults. I do not find this as the most optimal solution for me, since this would mean for me another setup of the controller along with FW update. Other factor is that work on PLCNext is part of my internship project, where I am investigating whether the platform would be a reasonable controller for my client’s products, hence any problems I encounter should be documented and be provided with a reasonable solution or prevention to it and (preferably) a root cause of it.

I have tried to run two different projects (one with IEC 61131 tasks only and other one with both C++ component task and IEC 61131 task) with different eHMI layouts, both gave the same (rather no) result.

As far as I remember I have not made any changes to configuration files. Also while looking at the Output.log I do not notice anything “wrong” going with the eHMI.
NB: Do I guess correctly that the HMI runs on port 9999? If so, is that a default one?

06.11.19 16:37:33.243 Arp.System.Acf.Internal.Sm.ProcessesController INFO - Library ‘Arp.Services.Ehmi.Library’ in process ‘MainProcess’ loaded.
06.11.19 16:37:35.300 Arp.Services.Ehmi.EhmiComponent INFO - EhmiComponent: EhmiComponent
06.11.19 16:37:35.301 Arp.System.Acf.Internal.Sm.ComponentsController INFO - Component ‘Arp.Services.Ehmi’ in process ‘MainProcess’ created.
06.11.19 16:37:45.522 Arp.Services.Ehmi.EhmiComponent INFO - 3055768576 Enter EhmiComponent: Initialize
06.11.19 16:37:45.524 Arp.Services.Ehmi.EhmiComponent INFO - 3055768576 Exit EhmiComponent: Initialize
06.11.19 16:37:45.525 Arp.Services.Ehmi.EhmiComponent INFO - 3055768576 EhmiComponent: SubscribeServices
06.11.19 16:37:45.525 Arp.Services.Ehmi.EhmiComponent INFO - 3055768576 Enter EhmiComponent: LoadSettings settingsPath=/etc/plcnex t/device/Services/Ehmi/ehmi.settings
06.11.19 16:37:45.537 Arp.Services.Ehmi.EhmiComponent INFO - 3055768576 Exit EhmiComponent: LoadSettings
06.11.19 16:37:45.538 Arp.Services.Ehmi.EhmiComponent INFO - 3055768576 Enter EhmiComponent: SetupSettings
06.11.19 16:37:45.956 Arp.Services.Ehmi.EhmiComponent INFO - 3055768576 SetupSettings Created directory ‘/var/tmp/ehmi’
06.11.19 16:37:45.963 Arp.Services.Ehmi.EhmiComponent INFO - 3055768576 SetThreshold level=6.
06.11.19 16:37:45.964 Arp.Services.Ehmi.EhmiComponent INFO - 3055768576 IndentSize=0
06.11.19 16:37:45.970 Arp.Services.Ehmi.EhmiComponent INFO - 3055768576 IndentSize=0
06.11.19 16:37:45.972 Arp.Services.Ehmi.EhmiComponent INFO - 3055768576 Initialize ehmiUsersBinPath=/opt/plcnext/projects/curren t/Services/__ehmiusers.bin, ehmiUsersBinFileServiceID=OSFileServiceID
06.11.19 16:37:45.972 Arp.Services.Ehmi.EhmiComponent INFO - 3055768576 PlcnextDataAccessService GdsAccessID=DataAccess, CacheTi meFactor=1, GroupTimeout=120000, NormalizeArrayIndexes=0
06.11.19 16:37:45.972 Arp.Services.Ehmi.EhmiComponent INFO - 3055768576 Exit EhmiComponent: SetupSettings
06.11.19 16:37:45.972 Arp.Services.Ehmi.EhmiComponent INFO - 3055768576 EhmiComponent: PublishServices
06.11.19 16:37:46.294 Arp.Services.Ehmi.EhmiComponent INFO - 3055768576 EhmiComponent: OnPlcLoading
06.11.19 16:37:48.364 Arp.Services.Ehmi.EhmiComponent INFO - 3055768576 Enter EhmiComponent: OnPlcLoaded
06.11.19 16:37:48.380 Arp.Services.Ehmi.EhmiComponent INFO - 3055768576 Load Loaded data.dictionary.json, variables=12
06.11.19 16:37:48.382 Arp.Services.Ehmi.EhmiComponent INFO - 3055768576 Exit EhmiComponent: OnPlcLoaded
06.11.19 16:37:48.565 Arp.Services.Ehmi.EhmiComponent INFO - 3055768576 EhmiComponent: LoadConfig
06.11.19 16:37:48.566 Arp.Services.Ehmi.EhmiComponent INFO - 3055768576 EhmiComponent: SetupConfig
06.11.19 16:37:50.788 Arp.Services.Ehmi.EhmiComponent INFO - 3055768576 EhmiComponent: OnPlcStarting, startKind=Warm
06.11.19 16:37:50.820 Arp.Services.Ehmi.EhmiComponent INFO - 3055768576 Enter EhmiComponent: OnPlcStarted
06.11.19 16:37:50.822 Arp.Services.Ehmi.EhmiComponent INFO - 3055768576 Exit EhmiComponent: OnPlcStarted
06.11.19 16:37:50.824 Arp.Services.Ehmi.EhmiComponent INFO - 3055768576 Enter EhmiComponent: Start
06.11.19 16:37:50.843 Arp.Services.Ehmi.EhmiComponent INFO - 3055768576 Enter Start.
06.11.19 16:37:50.843 Arp.Services.Ehmi.EhmiComponent INFO - 3055768576 Start BindPort=127.0.0.1:9999, InactivityTimeout=30000, MaxClients=10000
06.11.19 16:37:50.843 Arp.Services.Ehmi.EhmiComponent INFO - 3055768576 Enter OpenListenSocket.
06.11.19 16:37:50.843 Arp.Services.Ehmi.EhmiComponent INFO - 3055768576 OpenInetStreamSocket sock=0x2f
06.11.19 16:37:50.843 Arp.Services.Ehmi.EhmiComponent INFO - 3055768576 SetReuseAddr Sock=0x2f, reuseAddr=1, ok=1
06.11.19 16:37:50.844 Arp.Services.Ehmi.EhmiComponent INFO - 3055768576 SetLinger Sock=0x2f, linger=1, seconds=0, ok=1
06.11.19 16:37:50.844 Arp.Services.Ehmi.EhmiComponent INFO - 3055768576 Bind Sock=0x2f, to=127.0.0.1:9999, ok=1
06.11.19 16:37:50.844 Arp.Services.Ehmi.EhmiComponent INFO - 3055768576 Listen Sock=0x2f, backlog=10, ok=1
06.11.19 16:37:50.844 Arp.Services.Ehmi.EhmiComponent INFO - 3055768576 OpenListenSocket ListenSocket=0x2f, BindPort=127.0.0.1:9999
06.11.19 16:37:50.844 Arp.Services.Ehmi.EhmiComponent INFO - 3055768576 Exit OpenListenSocket. elapsed=1
06.11.19 16:37:50.844 Arp.Services.Ehmi.EhmiComponent INFO - 3055768576 Exit Start. elapsed=2
06.11.19 16:37:50.849 Arp.Services.Ehmi.EhmiComponent INFO - 3055768576 Clear
06.11.19 16:37:50.857 Arp.Services.Ehmi.EhmiComponent INFO - 3055768576 Load Loaded data.dictionary.json, variables=12
06.11.19 16:37:50.862 Arp.Services.Ehmi.EhmiComponent INFO - 3055768576 Exit EhmiComponent: Start

Kind regards,
Michael Czorniej

2

Hey Michael , that 127.0.0.1 9999 is the CGI to PLCnext FW connection.

So this should not have anything to do with the general availability of the site.
All this handles is feeding data between the ehmi and plcnext. The Ehmi Itself is listening on 443 for external incomming connections.
And the site contents should be found from “projects/PCWE/Services/Ehmi/ehmi/” even if the data are not refreshed. For details you can have a look at the /etc/nginx/ config.

The behavior you mention sounds like there is no Login-page setup in the PLCnext Engineer project and authentication is enabled.
What Version FW and Engineer are you using? Can you reach the wbm? Is the NGinx running?
Can you make sure that your project was downloaded “ls -la projects/PCWE/Services/Ehmi/ehmi/” What kind of error do you get when connecting with a browser?
kind regads,
Oliver

3

Hi Oliver,

Thanks for the reply.

I have the user authentication disabled in my eHMI setup and I had my solution already working without the login page.

What Version FW and Engineer are you using? Both are version 2019.9 Can you reach the wbm? Yes, no matter If try to access the eHMI via the IP address only or by specifying the path https:///ehmi/hmiapp.html Is the NGinx running? Yes it is running _
_ Can you make sure that your project was downloaded “ls -la projects/PCWE/Services/Ehmi/ehmi/” Yes, I can see that all my eHMI pages have been downloaded. What kind of error do you get when connecting with a browser? I get no error. I simply get redirected to WBM._
_

I checked the NGinx’s error logs and saw Access Denied error with the timestamp similar to the moment I was trying to access eHMI and suddenly I recalled one small thing. So apparently I did made a small change in the system’s configuration ? Namely, I had to change the permissions of the home folder /opt/plcnext from the default ones, since I was unable to make use of shared-key authentication for SSH client, by a mistake I did remove execute permission for other users, what apparently did not let the NGinx to serve the eHMI. I have restored it and the eHMI has started to show up again.

Thanks a lot for your help.

Regards,
Michael