Time out error

Hi, being first post on the form, I hope some of you boffins can help me with a frustrating problem. This is a machine that was bought and the manufacturer has long since gone, so no support. I will first describe the machine/PLC/PC setup.
OS: Win XP, SP3. Running a Visual Program through SQL 2008 express. The machine has a Control Techniques unidrive SP servo drive with an Ethernet and SP application modules installed. The I/O is Beckhoff with a CTNET bus coupler connected to the unidrive. The PC is connected to the Ethernet module through a 4-port switch (although we have tried it directly connected with a crossover cable). The Ethernet at each end is set to 100Mbps full duplex. The PLC program is installed in the SM applications module, which is complied in SyPTPro. Now to the problem: we randomly receive time out errors, which can be restarted on occasions by holding the start button for a period. On other occasions it simply hangs and has to be rebooted. We have noticed that there is a delay in the bits being set to 0 or 1 on a monitor window within the VB program, although we can see the I/O reacting immediately through the connected programming laptop. On rare occasions the error; 'No low level buffer free/resources available'.
Can anyone suggest where we should go from here to resolve this?

try running a continous ping on the connection while your running the aplication keep an eye on the TTL value. Timout errors can be casued either through poor connections or software delays in response times. watch your processes access see if there is a process that uses more resources just prior or during the timeout.

Will try on Monday. Now off for the weekend. (Some time out) !!!!

Hi,

If you want to send me your SyptPro project and i can have a look if there's anything i can see causing the problem.
Cheers
Paul