chanchungfat Posted October 6, 2009 Share Posted October 6, 2009 Hi, It's our first project using DAQFactory. And finally we come to the part of Modbus. There are 48 serial RTU slave flooding detection device based on pic16f876a. Each device has 4 points to be read. 1 = flood 0 = no flood. We create 48x4 channels to read the devices. An ethernet-RS-485 converter is employed. DAQ is running on Windows Vista. The problem is every time the system runs for a few minutes good. It then hangs up. And we notice that every hanging up is associated with a double receiving message, like this: TX(17:39:53.398): \x30\x03\x00\x05\x00\x02\xD0\x2B RX(17.39:54.791): \x30\x03\x04\x00\x00\x00\x00\xDA\xF0 RX(17:39:54.791): \x06\x80\xC1 The system hangs up at that point. However, we press a command button which is executing the command device.ModB.ConfigureComm(), the system resumes. The command/alert window do not show error messages except normal timeout. We have added a sequence constantly clear locked port but it does not work. We understand the problem may be originated from bus noise or the converter driver. Is there a means to reset the system automatically after encountering the above situation? Thanks Link to comment Share on other sites More sharing options...
This topic is now archived and is closed to further replies.