Experimental Physics and
Industrial Control System

"Mark Rivers" <[email protected]> · Thu, 11 Mar 2010 10:21:52 -0600

Hi Dominique,

I was thinking about this some more, and realized I may have
misunderstood your question.

When you say: 
> At each time there could be a few modbus tcp devices that 
> are not available during the vme startup.

Do you mean that they are not available for good reason, like they are
powered off, disconnected from the network, etc.?  And that the problem
is that it takes a long time for the driver to time out trying to reach
them?  If that is what you meant, then that is a separate problem, which
I confess I have not paid much attention to this in the past, because I
have assumed that the devices must be available for the IOC to function
correctly.

Let me know if this is what you meant and I will look into it and get
back to you.

Mark

-----Original Message-----
From: Dominique Touchard [mailto:[email protected]] 
Sent: Thursday, March 11, 2010 8:06 AM
To: Mark Rivers
Subject: IP asyn timeout connection

Hi Mark,

we are using the modbus tcp (thanks again for your software) to control 
a few dozen of devices from an EPICS  vme crate. We are testing now our 
configuration, and starting often the vme crate to change our test 
configuration. At each time there could be a few modbus tcp devices that

are not available during the vme startup.

There are a lot of waste time to wait for timeout connections during the

drvMobusAsynConfigure command.( I suppose) (for example, we are testing 
now 34 devices which owns 4 modbus functions, one global read and three 
discret writes. In this case, the startup could spend half one hour 
without any acces to the IOC)

I don't find where we can set the timeout for the first connection try.

Any help would be appreciated.

Thanks again.

Dominique Touchard.

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System