I am doing writes with the Omni Driver which sometimes take up to 20 minutes to successfully reach the slave device. We have timeouts of less than ten seconds, and very few communications errors being reported. Any ideas? Also sometimes get wrong response, that is wrong address responding intermittently.
What version of Lookout are you using?What type of flow computer are you connecting to? What is the baud rate used? What is the communication type, i.e modem or straight serial connection? what is the polling rate?
Here are a few troubleshooting tip:
- Make a display for the Update and COMMfail datamember - make sure that the poll rate is not too fast indicating that the device cannot keep up with the request sent trough the serial port. One way to make sure of that is to create a serial diagnostic file: http://digital.ni.com/public.nsf/websearch/c78573e7f80481ef86256a2900739e46?OpenDocument
You will be able to see frames of request/responses between lookout and the device,as indicated in the document. Hope that helps.
Cyril Bouton Ap plications Engineer National Instruments