Experimental Physics and
Industrial Control System

"Mark Rivers" <[email protected]> · Fri, 11 Nov 2011 13:08:49 -0600

I can't understand from the trace why it is crashing, since it seems to be at the line which is calling pasynOctet->flush, unless one of those pointers is corrupt?

Let me know what you find.

Mark

________________________________________
From: Szalata, Zenon M. [mailto:[email protected]] 
Sent: Friday, November 11, 2011 12:58 PM
To: Mark Rivers
Cc: [email protected]
Subject: Modbus - Beckhoff

Hi Mark,
I am running a test soft IOC which reads from a handful of Beckhoff modules.  Just recently it started to crash with segmentation fault.  Here is some of the gdb output looking at the core dump file:

Loaded symbols for /lib/libnss_files.so.2
Core was generated by `../../bin/linux-x86/bkh ./st.cmd'.
Program terminated with signal 11, Segmentation fault.
#0  0x00d5e9bd in writeRead (pasynUser=0x9095664, write_buffer=0x9094dd0 "", 
    write_buffer_len=6, read_buffer=0x9095028 "\003 ", read_buffer_len=8, 
    timeout=2, nbytesOut=0xb7e091c8, nbytesIn=0xb7e091c4, eomReason=0xb7e091c0)
    at ../../asyn/interfaces/asynOctetSyncIO.c:265
265         status = pioPvt->pasynOctet->flush(pioPvt->octetPvt,pasynUser);
(gdb) bt
#0  0x00d5e9bd in writeRead (pasynUser=0x9095664, write_buffer=0x9094dd0 "", 
    write_buffer_len=6, read_buffer=0x9095028 "\003 ", read_buffer_len=8, 
    timeout=2, nbytesOut=0xb7e091c8, nbytesIn=0xb7e091c4, eomReason=0xb7e091c0)
    at ../../asyn/interfaces/asynOctetSyncIO.c:265
#1  0x008a4834 in doModbusIO (pPlc=0x9094ca0, slave=0, function=3, start=4106, 
    data=0x90955f0, len=3) at ../drvModbusAsyn.c:1439
#2  0x008a33eb in readPoller (pPlc=0x9094ca0) at ../drvModbusAsyn.c:1087
#3  0x00178244 in start_routine (arg=0x9095fb0)
    at ../../../src/libCom/osi/os/posix/osdThread.c:282
#4  0x00c59832 in start_thread () from /lib/libpthread.so.0
#5  0x0075546e in clone () from /lib/libc.so.6
(gdb)

Before the crash this was printed in the console:

epics> 2011/11/09 05:34:58.852 drvModbusAsyn::doModbusIO port BKH3_3408 error calling writeRead, error=192.168.0.193:502 timeout: Resource temporarily unavailable, nwrite=6/6, nread=0
Segmentation fault (core dumped)

I think that this started when I connected a prosilica camera to the same network hub, a private subnet (192.168.0.x).
The camera is running continuously sending image data at 10 frames/s.
At this point I am not sure, how long it runs before crash.

I will let you know if I discover anything new.

Thanks,
Zen

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System