TCP Server with rajant radio

Mbed OS Best practice
1

Hello everyone.

I have a radio system which is accepting GPS data from an external TCP/IP server. My radio system is connecting via a VLAN network.

I’m using ublox- C027 as a TCP server to send the GPS data to my radio but I have an issue with the connection. The VLAN is already enabled on my mbed but when my server try to accept the connection from the radio(TCP client) the accept function returning the value -3001.

Here is my mbed program:

#include "mbed.h"
#include "gnss.h"
#include<string>
#include "EthernetInterface.h"
#include "rtos.h"
#include "TCPServer.h"
#include "TCPSocket.h"

// LEDs
DigitalOut led_1(P2_4);
DigitalOut led_2(P2_3);
DigitalOut led_3(P1_21);
DigitalOut led_4(P1_24);



// Static IP network variables
static const char*          mbedIP       = "10.5.248.45";  //IP 
static const char*          mbedMask     = "255.255.248.0";  // Mask
static const char*          mbedGateway  = "10.5.248.1";    //Gateway

static const char* recvIP = "10.5.248.121";

int main()
{
    pc.baud(115200);
    pc.printf("TCP server example\r\n");
    
    EthernetInterface eth;
    eth.set_network(mbedIP , mbedMask, mbedGateway );// my device address
    //eth.connect();
    
    if (0 != eth.connect())
        {
            
            pc.printf("Ethernet not connected\n\r");
            led_1=!led_1;
            return -1;
        }
    else
        {
            pc.printf("Connected Ethernet \n\r");
            led_2=!led_2; 
            
        }
            
    
    //pc.printf("The Server IP address is '%s'\r\n", eth.get_ip_address());
        
    TCPServer srv;
    TCPSocket client_sock[MAXCLIENTS];
    SocketAddress client_addr[MAXCLIENTS];
    
    int connectionStatus[MAXCLIENTS];
    
    char *buffer = new char[256];
    
    // Open the server on ethernet stack 
    srv.open(&eth);
    
    // Bind the HTTP port (TCP 80) to the server 
    srv.bind(10110);
    
    // Can handle x simultaneous connections 
    srv.listen(MAXCLIENTS);
    srv.set_blocking(false);
    //client_sock[0].set_blocking(false); 
 
    int numClient = 0;
    int rcount = 0;
    int scount = 0;
    
    // initialize connection Status for client
    for(int i=0;i<MAXCLIENTS;i++)
        connectionStatus[i] = 0;
    
    while(1)
    {
        for(int i=0;i < MAXCLIENTS;i++)
        {
            //pc.printf("coonection : %i/n/r",connectionStatus[i]);
            // if not connected accept connection
            if (connectionStatus[i] == 0)
            {
                pc.printf("accept : %i\n\r",srv.accept(&client_sock[i], &client_addr[i]));
                if(srv.accept(&client_sock[i], &client_addr[i]) == 0)
                {  
                    connectionStatus[i] = 1;
                    client_sock[i].set_blocking(false); 
                    //srv.set_blocking(false);         
                    numClient++;                    
                    pc.printf("Client Accepted %s:%d,%d\r\n", client_addr[i].get_ip_address(),client_addr[i].get_port(),numClient);
                    led_3=!led_3; 
                }
            }
            
            // if connected        
            if (connectionStatus[i] == 1)
            {                                             
                rcount = client_sock[i].recv(buffer, sizeof(buffer));
                if(rcount > 0)
                {
                    sprintf(buffer, "Hello Client %s:%d\r\n", client_addr[i].get_ip_address(),client_addr[i].get_port());
                    scount = client_sock[i].send(buffer, strlen(buffer));
                    led_4=!led_4;
                }
                if(rcount == 0) // client disconnected
                {
                    connectionStatus[i] = 0;
                    pc.printf("Client Disconnected %s:%d\r\n", client_addr[i].get_ip_address(),client_addr[i].get_port());
                    client_sock[i].close();
                    numClient--;                
                }                                                        
                if(scount < 0) // unable to send data
                {
                    connectionStatus[i] = 0;
                    pc.printf("Connection lost %s:%d\r\n", client_addr[i].get_ip_address(),client_addr[i].get_port());
                    client_sock[i].close();
                    numClient--;                
                }                                                        
            }
        }
 
        wait(0.5f);
    }
 
}

I’m using mbed os 5.15.6

Please, help me as I tried so many TCP server programs but nothing working with this radio system.

Your help will be really apprecieted.

Regards
Nada

2

Hello Nada,

nope, that is not from incoming connection, that is because you set the socket to non-blocking and then that method only inform you about no client is available.

Error -3001 mean

NSAPI_ERROR_WOULD_BLOCK
no data is not available but call is non-blocking

I saw here many of your topics about the VLAN but probably here is no one who has experience with VLAN on Mbed.

BR, Jan

3

Thank you Johnny for your reply.

So no one can help me in that matter even though now the mbed is supporting the VLAN.

Thank you again for your help. I will keep trying until I establish the connection and I’m not sure because my rajant is connected to a VLAN with specific number or not.

Regards
Nada