Experimental Physics and
Industrial Control System

William Lu <[email protected]> · Mon, 07 Nov 2011 15:16:31 -0500

Thanks Ben for your reply. I think you are right. The error messages

"indicate that the device is temporarily unavailable (for instance

because it is busy servicing another device/request/whatever)."

I did a test using 2 GPIB devices with one ICS 8065 gateway. Here is

what I found.

If I set the trigger mode of one of the GPIB devices to the mode in

which the device did not respond to the requests and the StreamDevice

system variables as below:

ReplyTimeout = 4000;
ReadTimeout  = 4000;
(or  ReplyTimeout = 5000; ReadTimeout  = 5000;)

I got the exact same error message as I saw in the real scenario:

"Permission denied clnt_stat 5...".

If I set the StreamDevice system variables as below:

ReplyTimeout = 3000;
ReadTimeout  = 3000;

I got a different error message: "No reply from device within 3000 ms".

I believe that they both mean that device was not responding within the

ReplyTimeout milliseconds. They are different perhaps because the

timeout events were handled by different functions in the device/driver

support. I prefer the latter error message than the former, which is

kind of misleading.

Thanks Ben again for your help.
William

On 11/03/2011 06:06 PM, Benjamin Franksen wrote:

Am Donnerstag, 3. November 2011, um 19:26:47 schrieb William Lu:

I use a softioc to control multiple GPIB devices through the ICS 8065
Ethernet-GPIB controller.  I use asyn 4.15 and StreamDevice 2.4.
Occasionally the ioc printed the messages like the following:

2011/11/03 13:36:59.001 INJGPIB1 vxi11 clientIoCall errno Permission
denied clnt_stat 5
2011/11/03 13:36:59.001 INJGPIB1 IFY0IA2iread: asynError in read:
INJGPIB1 RPC failed

2011/11/03 13:36:59.001 INJGPIB1 IFY0IA2iread: I/O error after reading 0
bytes: ""
2011/11/03 13:36:59.001 INJGPIB1 IFY0IA2iread: Protocol aborted

I am wondering what they mean. Why did I get them?

Probably they mean that your ICS 8065 is broken (though not fatally), possibly
due to a bug in the firmware. It should never happen that you /occasionally/
get "permission denied" errors from the RPC layer (which is what the VXI-11
protocol builds upon). One possibility is that the guys who wrote the software
(firmware) for the ICS 8065 misunderstood the specification and send back such
an error to indicate that the device is temporarily unavailable (for instance
because it is busy servicing another device/request/whatever). One way to
check this hypotheses is to temporarily switch to a configuration where you
use only one GPIB device per gateway: if the error goes away then this would
confirm my hypotheses.

Another possibility for research is to try to correlate the times these errors
happen with network problems, e.g. intermittent failures of network components
between the gateway and the IOC or unusually high rates of broken packages.
(Note that this is a pure guess, you should consult with your network people
and ask them whether they think this could be a cause.)

In any case, you might want to see if firmware upgrades for the ICS 8065 are
available. With the Agilent E2050A (another such gateway) this sometimes did
help to resolve problems.

Cheers
Ben

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--
Weiwei (William) Lu
Accelerator Controls Software Group
Jefferson Lab
757-269-7476

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System