Modbus - Beckhoff

["Szalata, Zenon M." <zms@slac.stanford.edu>]

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="" 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