Can't receive the data from my hardware device by LAN

Question

Hi!
background:  For a testing task, I set up a hardware testing platform that including of a power supply device, a hardware to be tested(Device Under Test), a power Meter and a PC.   i build a program to control the hardwares, and they communicate with each other by LAN. at first, the program as a client can normally communicates with my hardware after initializing all hardwares. And then the program turns off the power of my device and turn on power again after delay 60 seconds. after initiantion, my hardware can execute the command which is received from the program, but the program can't receive the data from my hardware. Why my program cannot receive the data from my hardware, after the second time turn on the power of my hardware?  the program as client code as below:
int CVICALLBACK ClientRRH (unsigned handle, int event, int error, void *callbackData)
  char temp[64]={0};
  int  ReceiveSize=0;
  char *Pos;
  switch(event)
   case TCP_DATAREADY:
    if( (ReceiveSize=ClientTCPRead (rrhHandle, readRRHBuffer, 4096, 2000))<0)
                 SetCtrlVal (panelHandle, PANEL_TEXTBOX_INFO,"Read RRH trace error!\n");  
                return 0;
    else
     if (ReceiveSize>4096)
      readRRHBuffer[4096]= '\0';
       else
       readRRHBuffer[ReceiveSize] = '\0';
    if (Flag)
      Pos = strstr(readRRHBuffer,orderString);
      if(Pos)
       //strncpy(temp,(Pos+ strlen(orderString)),maxSize);
       _mbsnbcpy(temp,(Pos+ strlen(orderString)),maxSize); 
       sprintf(receData,temp);
       *temp=0;
       Flag=0;
       maxSize=0;
       *orderString=0;
    SetCtrlVal (panelHandle, PANEL_TEXTBOX_INFO,readRRHBuffer);
    *readRRHBuffer=0;
            break;
         case TCP_DISCONNECT:  
   rrhHandle =error;
            SetCtrlVal (panelHandle, PANEL_TEXTBOX_INFO,"TCP Clienterver has closed connection!\n");                 
            SetCtrlVal (panelHandle, PANEL_LED_RRH, 0);      
            break;
 return 0;
int RRH_ini(char *RRH_address)
    ViChar Buffer[200];
    char temp[200];
    int status =0;
 if((ConnectToTCPServer (&rrhHandle, 7006, rrhAddr, ClientRRH, NULL, 1000)<0))
     SetCtrlVal(panelHandle,PANEL_LED_RRH,0);
    SetCtrlVal(panelHandle,PANEL_TEXTBOX_INFO,"Connection to RRH fail...\n");
     else
     SetCtrlVal(panelHandle,PANEL_LED_RRH,1);
     SetTCPDisconnectMode (rrhHandle, TCP_DISCONNECT_AUTO);
     sprintf(RRHCommand,"%s\n","asb");
     ClientTCPWrite (rrhHandle, RRHCommand, strlen(RRHCommand), 0);
     Delay(0.2);
     sprintf(RRHCommand,"%s\n","asb#1234");
     ClientTCPWrite(rrhHandle,RRHCommand,strlen(RRHCommand),0);
     Delay(0.2);
     SetCtrlVal(panelHandle,PANEL_TEXTBOX_INFO,"Connection to RRH successful!\n");
   return 0;

Answer 1

Yes that's exactly my problem. The reader sends bytes but without a delimiter. So for example the greeting message I've mentioned earlier "iiAWID..." happens to be 32 bytes, therefore I made the following changes to the code:
public void receive(int x){     // x = expected length of bytes being received
boolean done = false ;
int limit = x ;
int counter = 0;
try {           
while (!done)
if (in.ready())
buffer.add(in.read()) ;
counter = counter + 1 ;
if (counter == limit)
done = true ;
}catch(IOException e) { // some code for handling}
and this works fine, however, I'll probably have problems reusing this method later on, because some commands that I will send to the reader will result in responses of indefinite sizes. So I may have a response of length 12 one time and of length 8 the other. but between each response there's a maximum delay of 100ms... is there any way I can utilize that piece of information to improve my code?