Generator troubleshooting, repair, and discussion with a focus on Kohler standby systems

Caspian Live Generator RDC Monitor is progressing quickly.

We have identified most fields and are populating a panel with values, getting updates as fast as the RDC sends the data and we are refreshing the display every 5 seconds. This is significant. The Kohler PWR MGT App does not update the values anywhere near that quickly and we get the updates before they reach the Kohler Server. We could do it faster but we want to avoid excessive screen flicker.

We are confident now that we will be able to safely write changes to some of the RDC settings including Date and Time, All Exercise Scheduling parameters, And possibly start an exercise.

After examining the firmware file contents it does not appear that there is a writable memory location to allow mode switching.

Hi Caspian - appreciate all you are doing here. I just got a Kohler 38RCLC installed with a hard wired ethernet line. I happen to be a network geek, so I can help with packet captures, etc. I'm hooked into a switch with mirroring capabilities, so I can see everything going across the wire. Let me know how I can be of help/validation of all the good work you have done so far.

networkguru wrote: Fri Jul 10, 2026 10:44 am Hi Caspian - appreciate all you are doing here. I just got a Kohler 38RCLC installed with a hard wired ethernet line. I happen to be a network geek, so I can help with packet captures, etc. I'm hooked into a switch with mirroring capabilities, so I can see everything going across the wire. Let me know how I can be of help/validation of all the good work you have done so far.

Super!, Glad to have you!, I have two building projects going on and I and my queen run a non profit to build a war memorial that is eating up a bunch of our time so I had to set the project aside again for awhile, hoping to get back to it soon.

I have the new monitor functioning at about 90 %. It only requires what you have for hardware, smart switch with mirroring.

Please Hang in here with me , I try to find in an hour or two when I can. I think you will be pleased with this monitor, I already use it . One of the features I like a lot is the logging, That allows recording trends on a spreadsheet of the various telemetry items such as oil temp, current. rpm, etc. This version will cover Kohler Generators up to 38 KW Liquid and Air Cooled. When I get closer, I will provide you with a free copy to test with your generator If you stay with it, you will get a unlimited no expiration copy at no cost when the first release is made public. I am using a 26KW 26RCAL And a 38RCLC RDC for development. The 26 is on my generator, the 38 is on my test bench.

If you can provide me with pcapng files from wireshark that will help a lot, Especially if you capture at the start and end of an exercise or a auto started run due to a power failure.

Thanks!

I was able to find the Kohler parameter mappings. I posted them here: https://github.com/andrewroydshayes/rdc ... h/issues/2

I’ve started using AI coding agents and it’s amazing what can be done to make progress here. I have modified the rdc-proxy project and have logging to an influxdb instance with a front end web UI. Learning new things about this project every day and passing along what I’ve learned.

Good, If you have time I would still like wireshark .pcapng files at the start and end of an exercise or a auto started run due to a power failure.

Your mapping will also be useful , although I have an RDC for the same generator you have, since t is not connected to a generator, I would like to see values changing for some of the parameters such as oil pressure and coolant temp while the generator is running. Most helpful now would be a wireshark capture and set output capture to a file.
Thank you

I still have my plate exteremly full with some summer projects so I don't have much time to spend on this daily.

networkguru wrote: Fri Aug 14, 2026 7:28 pm I was able to find the Kohler parameter mappings. I posted them here: https://github.com/andrewroydshayes/rdc ... h/issues/2

I’ve started using AI coding agents and it’s amazing what can be done to make progress here. I have modified the rdc-proxy project and have logging to an influxdb instance with a front end web UI. Learning new things about this project every day and passing along what I’ve learned.

I responded too quickly to this, having not yet looked at your mapping chart .... plate too full syndrome

The important implication is that the RDC parameter space appears to be shared across generator families. That explains why the table contains items my 26RCA may never use, such as coolant-related parameters, three-phase L2/L3 measurements, and some larger-set configuration options. The same controller firmware/object model can expose a broad set of parameters while the installed generator personality determines which ones are valid or populated.

These mappings you provided will be extremely useful going forward to make the RDC monitor, and eventually OnCue emulator universally useful for the entire Kohler Commercial and residential Generator family. Great Work! Thank you, Now if I can just get some time to get back on this project .....

@networkguru

I have been putting in more time on this the last few days when I can.

Since you offered to help I am ready to share my work so far on the monitor only version, Here is a screen shot of the DEV RDC UI. Not the final UI but I use this to see what works and what does not.

This is monitoring the 38KW RDC on my desk so some values are not accurate since it is not connected to a generator, It is connected to Kohler's ONCue server at devices.kohler (rehlko) .com

If you are still with me on this I will send you a protected copy of the runtime, just understand I am not releasing this to the public domain so it must not be shared on any website including github.

I would still like some .pcapng files from your wireshark captures and I would like you to configure the output to a file as shown in the other image here. Choose any file name and path you like. [/img]

I would like you to leave it capturing for 12 hours, zip all the .pcapng files and upload them here if not too big, otherwise I will give you an upload link to one of my Synology NAS boxes

Just let me know if you want the dev monitor and if you are still willing to capture and share traffic for this project,