Experimental Physics and
Industrial Control System

Florian Feldbauer via Tech-talk <tech-talk at aps.anl.gov> · Tue, 4 Jul 2023 09:05:47 +0200

Hey all,

we have some devices controlled via CAN bus.

Since CAN bus is based on the transmission of 1-8 bytes, I wrote an

AsynPortDriver with an asynOctet interface as lower level driver.

I wanted to use StreamDevice as higher level driver defining the actual

payload data that is tranmitted between our PC and the devices.

Sending and receiving messages in principal works, but I have an issue

with I/O Interrupts and I don't know why.

Setting the streamDebug variable to 1, I see the following output from

StreamDevice:

2023/07/04 08:54:44.301618 can1 AsynDriverInterface.cc:951:

AsynDriverInterface::readHandler(CAN1:TEST:R): ioAction=AsyncRead

read(63 bytes, timeout=0 sec) returned status asynSuccess: received=4

bytes, eomReason=NONE, buffer="<07><00><00><ea>"

2023/07/04 08:54:44.301765 can1 AsynDriverInterface.cc:977:

AsynDriverInterface::readHandler(CAN1:TEST:R): AsyncRead poll: received

4 of 63 bytes "<07><00><00><ea>" eomReason=NONE [data ignored]

2023/07/04 08:54:44.301889 can1 AsynDriverInterface.cc:1123:

AsynDriverInterface::readHandler(CAN1:TEST:R) readMore=-1 bytesToRead=63

2023/07/04 08:54:44.302015 can1 AsynDriverInterface.cc:951:

AsynDriverInterface::readHandler(CAN1:TEST:R): ioAction=AsyncRead

read(63 bytes, timeout=0.5 sec) returned status asynTimeout: received=0

bytes, eomReason=NONE, buffer=""

2023/07/04 08:54:44.302140 can1 AsynDriverInterface.cc:1051:

AsynDriverInterface::readHandler(CAN1:TEST:R): ioAction=AsyncRead,

timeout [0.5 sec] after 0 of 63 bytes ""

2023/07/04 08:54:44.302262 can1 StreamCore.cc:963:

StreamCore::readCallback(CAN1:TEST:R, StreamIoTimeout input="", size=0)

2023/07/04 08:54:44.302378 can1 StreamCore.cc:1015:

StreamCore::readCallback(CAN1:TEST:R) inputBuffer="", size 0

2023/07/04 08:54:44.302490 can1 StreamCore.cc:1067:

StreamCore::readCallback(CAN1:TEST:R) end flag received

2023/07/04 08:54:44.302605 can1 StreamCore.cc:1127:

StreamCore::readCallback(CAN1:TEST:R) input line: ""

2023/07/04 08:54:44.302726 can1 StreamCore.cc:1151:

StreamCore::readCallback(CAN1:TEST:R) async match failure: just restart

2023/07/04 08:54:44.302847 can1 AsynDriverInterface.cc:806:

AsynDriverInterface::readRequest(CAN1:TEST:R, 500 msec reply, 500 msec

read, expect 0 bytes, async=yes)

2023/07/04 08:54:44.302964 can1 AsynDriverInterface.cc:831:

AsynDriverInterface::readRequest CAN1:TEST:R: queueRequest(...,

priority=0, queueTimeout=-1 sec) = asynSuccess [async=true]

The readHandler reads the message from the bus but ignores it. According

to the comments in the code it is ignored because the asyncReadHandler

should also receive this message and handle the I/O interrupt, but it

seems the Interrupt callback is not executed.

Any idea why the callbacks don't work?

I'm using
base 7.0.6.1
stream 2.8.24
asyn (current HEAD on master branch)

Cheers,
Florian

--
Ruhr-Universität Bochum
AG der Experimentalphysik I
Dr. Florian Feldbauer
NB 2/131 / Fach 125
Universitätsstr. 150
D-44801 Bochum

Office: NB 2/134
Phone:  (+49)234 / 32-23563
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Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System