This project has moved and is read-only. For the latest updates, please go here.

SEL Fast Message Errors

Jul 2, 2013 at 6:42 PM
When connecting to an SEL device using SEL fast message I get so many errors that the stream is unviewable. I have connected to both an SEL-734 and an SEL-351A over tcp/telnet and RS-232 serial. These are the Serial errors.

Attempting connection to "ID 1 using SEL Fast Message over Serial" at 7/2/2013 12:24:33 PM using SEL Fast Message
Connected to device "ID 1 using SEL Fast Message over Serial" at 7/2/2013 12:24:33 PM using SEL Fast Message
Exception: Bad data stream, expected header bytes 0xA546 as first bytes in SEL Fast Message frame, got 0x920B
Exception: Data channel user unhandled exception: Value cannot be null.
Parameter name: dst
Exception: Data channel user unhandled exception: Value cannot be null.
Parameter name: dst
Exception: Data channel user unhandled exception: Value cannot be null.
Parameter name: dst
Exception: Data channel user unhandled exception: Value cannot be null.
Parameter name: dst
Exception: Invalid binary image detected - check sum of DataFrame did not match
Exception: Invalid binary image detected - check sum of DataFrame did not match
Exception: Invalid binary image detected - check sum of DataFrame did not match
Exception: Invalid binary image detected - check sum of DataFrame did not match
Exception: Data channel user unhandled exception: Value cannot be null.
Parameter name: dst
Exception: Invalid binary image detected - check sum of DataFrame did not match
Exception: Invalid binary image detected - check sum of DataFrame did not match
Exception: Invalid binary image detected - check sum of DataFrame did not match
Exception: Invalid binary image detected - check sum of DataFrame did not match
Connection closed.

If somebody is willing to fix this I can provide you a stream capture, wireshark frames, or whatever you need. I could also test it for you.
Jan 6, 2014 at 4:06 PM
Is this still an issue? We made some enhancements to these protocols over the last year...
Jul 9, 2014 at 3:49 PM
Ritchie,

Yes this is still a problem with the most recent version of PMU connection tester ( 4.5.4.0). After consulting with SEL it turns out that when you transmit SEL-FM via the ethernet port it embeds it in a telnet stream, so all 0xFF bytes are duplicated for telnet compliance. This is why there are checksum errors. If the packets are sent via serial link this problem does not exist.

I verified that the problem could be fixed by writing a relay script to intercept the stream, search for consecutive 0xFF bytes, remove on of the 0xFF bytes and resend the packet. PMU connection tester and openPDC manager can both connect to the stream without errors now.
Jul 10, 2014 at 2:37 PM
We've seen similar behavior in other protocols - should be easy enough to get the protocol parser to ignore duplicated 0xFF bytes. I will add this to the TO-DO list.

Thanks!
Ritchie
Jul 10, 2014 at 4:13 PM
FYI - I've compiled a fix - if you can test binary updates in PMU Connection Tester, that would be great. Fix can be downloaded from here:

https://www.gridprotectionalliance.org/NightlyBuilds/Temp/SELPhasorUpdates.zip

Note that this update will only work using very latest version, v4.5.4.

To apply to PMU Connection Tester, make sure application is not running and unzip contents to the installation folder (this will usually require admin rights, depending on installation location). I suggest backing-up old binaries in case this doesn't work - otherwise you may have to reinstall.

Would rather not test on your openPDC just yet as there may be more binary changes needed that I provided in the zip update. If this works I will provide a new BETA build of the openPDC that includes this fix.

Thanks,
Ritchie
Jul 10, 2014 at 4:31 PM
Fantastic. I have let it run about 10 minutes and only got one error (as opposed to 10+ per second before). The error was when the connection was first established and from the exception it looks like it is flagging the telnet connection handshake as a bad C37 header, but that can be ignored and won't cause any real problems.

Attempting connection to "ID 7218 using SEL Fast Message over Tcp" at 7/10/2014 10:27:21 AM using SEL Fast Message
Connected to device "ID 7218 using SEL Fast Message over Tcp" at 7/10/2014 10:27:21 AM using SEL Fast Message
Exception: Bad data stream, expected header bytes 0xA546 as first bytes in SEL Fast Message frame, got 0xFFFB

Thanks a ton, this has been causing me grief off and on for a year! I would appreciate a beta release of openPDC with these updates whenever you get a chance.
Aug 4, 2014 at 10:07 PM
Latest openPDC and PMU Connection Tester downloads now have this fix.

Thanks!
Ritcihe