Re: Digi Connect ME - Querry

Embedded Devices Plug N' Play
1

Hi

We have developed access control system where central controller is collecting data fro readers and communicates to server as & when data arrives at reader.

To communicate data to server we are using Digi Connect ME modules to transmit data over TCP/IP network.

Server application is developed in Visual Basic & We are using Winsock control to listen /connect with Digi Connect ME modules.

It works fine if Digi Connect ME is ON and network is OK,

:: Problem ::

If due to power failure Digi connect ME resets, existing connection with server application gets closed & server is not notified in any way this connection is lost

And server is not able to receive data on already open port, unless server application is closed & opened again to re-establish connection.

As server is ideally not monitored everday & should recover from such errors automatically I would like you to suggest any remedy we can use in our application…

  1. either we get notification once digi connect ME restarts
  2. server can know status of modules if they are connect & working OK
  3. any other suitable methid that can help to recover.

LOOKING FORWARD TO YOUR REPLY

  • Mohan, Bangalore-India
2

It sounds like your question is entirely VB-related, so I don’t think there’s anything you can necessarily do on the ME side of things. One thing you could do is add a timeout value to your sockets: if a data transaction doesn’t occur in some amount of time (like maybe 20 seconds if it normally occurs every 2 seconds when the ME is up and running normally), then assume the ME is off-line and close the socket.

Darrin

3

Turn on TCP keep alives in your VB application. This will help your applicaiton realize the socket has gone bad and then you can put in code to reconnect (or re-accept) a new socket connection.

If the problem is with the ME no longer accepting a new connection, try enabled TCP keep alives on the ME.