Experimental Physics and
Industrial Control System

[email protected] · Mon, 15 Aug 94 16:53:07 -0500

This 0x1a9 stuff seems to have come back up.

>   If you reboot your IOC too early you get the following message:
>
>   Loading... 
>      Error loading file: errno = 0x1a9...

I researched this stuff a while ago.

Apparantly, the boot roms use the EXACT same port and window offset
when opening an FTP socket to a server... which then can't figure what
it is supposed to do and things lock up for the timeout duration on the
FTP server.

The *solution* to this would be to have wind rivers write a better boot
procedure for the ROMs.

The cause of the confusion is that you can not reboot an IOC while the
startup.cmd file is running.  After it is done, the ftp session is
terminated and the server process dies... thus closing that socket.

We (Ken, Frank and I) figured this out by watching the packet-flow b/w
the IOC and the boot server along with the ftpd process's status on the
server.  There was no HARD evidence to support my above description,
but EVERY low-level TCP/IP book that discusses error recovery talks
about this situation and how to deal with it... reusing the same
port and window offsets is the worst thing you can do.

--John

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System