Connecting Scada-LTS values to OpenPLCv3 Program

[athomsen115]

I am having some issues getting my PLCs and Scada-LTS (v2.7.8.1 build 14176899126) to talk to each other and I could really use some help getting this off the ground. I am trying to use this for a learning environment range for a cyber course I teach at.

All my values are displaying as 0, and I am unable to get my HMI to update any values on my PLC even when marked as settable. I unfortunately cannot provide screenshots of my HMI setup as it is running in an offline range environment.

I am running a modified version of GRFICSv3 in my own environment. Here are the PLC files that I am running in OpenPLCv3 runtime:
PLC1_SourceWater.st.txt
PLC2_ChemicalDosing.st.txt
PLC3_Tank.st.txt
PLC4_WasteStream.st.txt
PLC5_TreatedWater.st.txt
The PLCs are simply ubuntu servers with openplc runtime v3 and I am just uploading the programs I have written and starting the PLC.

I am just going to use SourceWater as my test case, because if I can get one working, I can make the rest work. These compile and appear to function. Under the monitoring tab of the OpenPLPC web view, I am able to see the values. Inside SourceWater, I have a HMI_Level_SP value. This is designed to be updated by the HMI and adjust the rest of the program values. I was unable to get the values I set on the HMI to write to the PLC.

Here is what I have tried so far:

• Created a data source: Source Water --> Host set to PLC IP Address XX.XX.95.6 and port 502
• Creating a setable data point

1. HMI_Level_SP is set to a numeric Data Type, Slave ID: 1, Holding Register, Offset 11.

• Here are what my other data points are set to, paired to the values I put in my program

2. Source_Flow: numeric Data Type, Slave ID: 1, Holding Register, Offset 50
3. Source_Pressure: numeric Data Type, Slave ID: 1, Holding Register, Offset 54
4. Source_Valve_Pos: numeric Data Type, Slave ID: 1, Holding Register, Offset 52

• Creating a point event detector on HMI_Level_SP to detect on change
• -- This required me to add a virtual data source HMI_Input : HMI_Level_SP_Input
• ---- I moved the point event detector to this data point
• Adding an event handler to 'Set Point' when the source changes to set point on the HMI_Level_SP address
• Adding a script that says "dp.writeDataPoint('DP_{HMI_Level_SP}', p38); where p38 corelates to the virtual data point. This script did not appear to work as intended and in my watchlist, the value of HMI_Level_SP does not change.
• Adding a graphical server-side script with settable override (not sure if I needed this one) and display controls that relates to the HMI_Level_SP_Input virtual data point. This then updates and I expect it to run my script, but no values change on the PLC side.

Additionally, for testing purposes, I hard-coded the value of HMI_Level_SP into the PLC program. This updated all the monitoring values on my OpenPLCv3 runtime environment, however, none of the values on the HMI display changed and everything is still reading as zero.

Ideal end state is that the PLC and HMI are able to update each others values. I would like the HMI_Level_SP to be adjustable by a "technician" in the HMI display, but also, it can update itself within a range of values so that the information is changing and updating as a flowing water plant would.

I am really hoping someone can help me. Please let me know if there is more information I can provide or if I am doing something wrong even at the PLC level.

[AbilIT-Dawid]

@athomsen115 Thank you for using our SCADA‑LTS environment.

You may want to start with version 2.8.1, which is available via Docker.
There are some major updates, and it would make sense to go with this version. It is not final yet, but I encourage you to test it.

We could also move this topic to email for direct support regarding your educational efforts. You can contact us via one of our official email addresses: @SCADA-LTS .com or .org.

Thank you — your effort really matters to us.

[athomsen115]

Thank you for reaching out to me. I have sent this to ***@***.*** as it was the only email I could find, but I am not sure if it is the right one. Given my disconnected environment, that is why I chose to use the manual build option. I am open to considering that in the future, but I believe I would have to rebuild my whole VM on my home computer and bring that into range, which will not be a quick process. If there is a way to download the docker image onto a CD and transfer that over, that might be an option. I have never built or fully interacted with an HMI before, so I feel like there is definitely a knowledge gap affecting my ability to make this work. I am not sure if a Holding Register is the right register to have placed the value in. When I do point lookup from my datasource, it always returns zero, even after I have my PLC running with non-zero values. I would really appreciate any help that can be provided. Very Respectfully, Alexa Thomsen Cyber Threat Hunter

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On Fri, 20 Mar 2026 at 01:18, AbilIT-Dawid ***@***.***> wrote: @athomsen115 <https://github.com/athomsen115> Thank you for using our SCADA-LTS environment, Maybe you would like to start with our 2.81 which is available at docker? There are some major updates and it would make sense to go with this one ,it is not final yet but i encourage you to test it. Also, we could move this topic on emails for direct support on your educational effort. You can contact via one of our official emails. @Scada-lts.com / @Scada-LTS.org Thank you, your effort matters for us. — Reply to this email directly, view it on GitHub <#3254?email_source=notifications&email_token=ANRMSYYUFOTYYO2EMNLSAZL4RT5EXA5CNFSNUABIM5UWIORPF5TWS5BNNB2WEL2ENFZWG5LTONUW63SDN5WW2ZLOOQXTCNRSGIZDEOBVUZZGKYLTN5XKO3LFNZ2GS33OUVSXMZLOOSWGM33PORSXEX3DNRUWG2Y#discussioncomment-16222285>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ANRMSY7QCPQQN76RZDOYTN34RT5EXAVCNFSM6AAAAACWYEQQ4WVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTMMRSGIZDQNI> . You are receiving this because you were mentioned.Message ID: ***@***.***>

[AbilIT-Dawid]

Dear Alexa,

I'm trying to find your email but I'm not sure where it went. I was sure you will enter scada-LTS website as advised, there you can find email, also docker with both stable and development version ( 2.81 )

For the offset, try to add 1024 to your values, so 1074,1076.. but as i suggested, it would be better to swap on email.
Thank you

Best regards
Dawid Dajer