MATLAB: No Signal on rs232 serial connection from xPC

fifo overflowrs232serial portsimulinkSimulink Real-Timexpc

Hello
I am trying to to connect xpc over rs232 to a bus called bus2. A connection with matlab and its serial function worked flawless, it was possible to send and receive messages on/to the bus and an oscilloscope connected to the bus showed me all signals. At the moment I am trying build a model with simulink to send a message on the bus with the xPC Target library and the Baseboard serial module. To test if any signal goes on the bus, I used the demo model "xpcserialbaseboardsimpleascii.mdl" deleted the receiving blocks for Com2 compiled and uploaded on my xPC Target which is a standard PC with one serial port.
The problem is that when I start the Model there isn't any signal on the bus, the oscilloscope shows no activity on the bus or when connected direct on the serial port. the only error xPc shows is "FIFO overflow: XMT channel 1, IRQ 4". The RTS/CTS box of the module is unchecked since it is only a 3 wire connection.
Does the Baseboard serial module wait for an extra handshake before flushing out the buffer even the RTS/CTS box is unchecked or did I misunderstood the whole concept?
thanks

Best Answer

If you're using MATLAB R2012a, then there is an issue in the code generation for interrupt handling that affects the serial blocks.
See the bug report number 826451 and download the patch file.
If you're not using R2012a, then you need to contact tech support for more assistance.