I have written a test applicaiton in VB.NET 2005 to use the ZStar boards. Other than what I believe to be a bug in the Port.Read command (for which I have a work-around), everything is working well. My question is this: How do I query the stick to determine if the sensor board is present? It seems that once data has been received from the remote board, the 'V' command will keep returning the last vaues received from the sensor baord. In fact, the 'r' command seems to return 'z', even once the sensor board is turned off.Thanks.