Is Serial port.BytesToRead doesn't receive proper bytes?

It simply means that 24 bytes are actually sent. It has nothing to do with baudrate and other parameters (which should of cause match). The remaining bytes might come later, or never, as guided by the logic of the device. Best way is to read all you have in buffer in raw bytes and analyze as you receive them.
--SA

i have used encoding.UTF8 but it doesn't work.i have used device and simulator using serial port.device will send 47 bytes but in simulator i have used serialport.BytesToRead to read bytes from device but in simulator it reads only 24 bytes based on tht it performs execution but at nxt time device will send next bytes .but in serialport.BytesToRead the remaining 23bytes+other bytes send will be received and performs operation but it is wrong.how can i do in serialport to read all 47 bytes at one slot and perform operation.and bytes are getting appended how can i clear in serialport.and other thing is bytes 47 is an example not always 47 bytes is received it will vary based on input .i should wait till all bytes received and perform operation how can i accompalish?? -this is through loop back cable.but when i does through virtual com port it is working fine.but i need to do through loopback cable