RE: Asyn record CNCT field does not update

[Mark Rivers via Tech-talk <tech-talk@aps.anl.gov>]

Hi Abdalla,

 

This is a common problem and occurs because drvAsynIP port is relying on the OS to report whether the port is connected or not.  When you disconnect the cable or power off the device it takes time before the OS reports that it is disconnected and closes the socket.  As I recall, on Windows this time is less than a minute, but on Linux it can be hours.  A solution is to set the asyn option disconnectOnReadTimeout=Y on the drvAsynIP port.  That will cause drvAsynIP to close the socket immediately if there is a read timeout.  If the port has autoConnect=1 then the next I/O operation will try to re-open the connection.

 

Mark

 

 

From: Tech-talk <tech-talk-bounces@aps.anl.gov> On Behalf Of Abdalla Ahmad via Tech-talk
Sent: Tuesday, November 25, 2025 11:37 AM
To: tech-talk@aps.anl.gov
Subject: Asyn record CNCT field does not update

 

Hi

 

I developed an asynPortDriver to control a device through UDP, I want to use asynRecord CNCT field to monitor the port connection state whether the device is connected or not. The driver is configured with auto connect flag set to 1. When I monitor the field and disconnect the device, I get error message indicating IO error, but the field does not change to disconnect. I am I missing other settings to be done?

 

Best Regards, 

Abdalla.