ELEKTOR FORUMS

Dear All,
I am writing to enquire about the use of an OBD-Analyser i am working with as part of my Final year college project. The OBD-Analyser i am using is called OBD-2-Analyser (050092-71) and was ordered online at Elektor electronics. With this i am using a Mobydic adaptor. I have successfully read in diagnostic data from a car using this equipment with some downloadable software. My project requires that i must write my own software to communicate with the car.
I am using Visual Basic 6.0 and can successfully transmit hexadecimal messages via the USB-RS232 connection which is connnected to the OBD-Analyser. Unfortunately i have yet to receive any data. I have been testing solely with the ISO9141-2 protocol and am unsure of the correct messages i need to transmit so as to perform initialisation and to perform a successful request message. Any suggestions would be greatly appreciated.
Furthermore, can you tell me whether it is a requirement of the software to 'keep-alive' the communication or can the hardware i am using perform this?
Once again, your help would be much appreciated.