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Historian under POSIX

May 3, 2015 at 3:51 PM
I'm getting closer... one of these days I'll have it wrapped up. I appreciate the help so far.

I've got an SEL-421 PMU with a built-in Ethernet adapter streaming data to my Raspberry Pi, and it seems to be working fine as an input and I can see the output through the Pi with the PMU connection tester (I connect to the Pi with PMU Connection Tester and can see frequency at 30 fps, for example).

Now, I am trying to warm up the Historian. Via the openPDC Manager, I've changed the default Pi image Type and Assembly names in the PPA Historian Instance to the respective HistorianAdapters configuration (rather than the Test adapters), and now my /Archive directory has .d files written, but these files don't seem to contain any data from my PMU, and the "date modified" isn't changing. Looking at them in either Historian Playback, Historian Trending, or exporting to CSV, I get nothing (or NaN in some instances). Any suggestions?


May 3, 2015 at 7:14 PM
Edited May 3, 2015 at 10:07 PM
Looks like a reboot of the Pi has helped (and was all I needed). I'm now archiving data. Almost there...

Next step is to see if I can hook /dev/ttyAMA0 of the Pi to a serial port on a SEL-421.

Edit: Can't seem to get /dev/ttyAMA0 to be 'accepted' as a communications port by openPDC. Can't find where it's a permitted COM port in the documentation either (I see COM1 type ports, but no /dev/tty ports). Anyone here know about that? I've got a MAX3232 based adapter for my Pi, and I know it works (I can use Minicom on the Pi to communicate with a console port on the relay).

For my testing for now, the Ethernet is fine, but in the future, I'd like to use RS232 if possible, as the relays I have in mind do not have Ethernet on them and I'd prefer to avoid serial to ethernet adapters.
May 4, 2015 at 1:04 AM
I've never tested the serial communications on Linux - I suspect there's a way to pick up the /dev/tty/AMA0 style ports - or a .NET way (perhaps in the config) to map them to COMx style ports.

May 4, 2015 at 1:29 AM
Edited May 4, 2015 at 2:04 AM
Thanks Ritchie. I just tried ser2net as a /dev/tty redirector to IP, and it would start to work very briefly and then errored out on checksum with PMU Connection Tester, using the Pi as a serial to Ethernet converter - I'm thinking I could direct openPDC to the TCP port of localhost, which would be redirected by ser2net to the /dev/ttyAMA0.

I'll keep messin' with it. :)



Edit - turned off all flow control and it seems to be stable with PMU Connection Tester. Now to see if it'll work in openPDC...

Aaand... it's working. :) PMU Connection Tester is able to get data from Pi port 8900.

I used this technique to get ser2net on the Pi:

Link to how to get ser2net loaded, configured, and running on the Pi

My only difference was in the configuration file, I used -XONXOFF to turn it off -