RA FREERTOS Ethernet issue

Question

Hi support team 
 
 I am using the EK-RA6M4/5 ethernet example project, the FSP is 5.1~5.3. The EP is showing the FreeRTOS and TCP/IP stack. The EP can be found on the renesas official website. 
 I can't do the TCP/UDP communication when the "Network is up". I found that i must wait 4~7 seconds when the IP assignment is done(No matter the DHCP is enable or disable). 
 
 May i know why i need to wait 4~7 seconds even if "Network is up" and is it a normal status? 
 
 Attach my project. 
 
 Thanks.

IK_Renesas · Answer

Hello sir, 
 After checking your project in more detail. I would say that generally it seems that it is working fine with no issues. After making changes to the network setting so that I would adjust it in my network. I was able to connect and send messages to TCP server and also receive messages from the TCP server.

Regarding the delay please let me inform you that in your code you have left a while loop probably trying to do some ping requests after the IP of the device is resolved.

In general ,after the successful creation of the TCP socket, the client needs some time to be able to connect to the TCP server and start the communication. 
 What also plays important role is when the TCP server running on the other device is initiated-started and is listening to incoming connections. 
 If you will check the documentation of FreeRTOS+TCP stack it is mentioned that this API has an optional time out with a default value. 
 www.freertos.org/.../connect.html 
 The time that a TCP client needs to connect to TCP server, depends also on what state is the TCP server from the other side if it is already ready to be listening to connections and it is not fixed every time that the client reconnects to the TCP server. 
 As mentioned in the documentation of the FreeRTOS+TCP stack if the connect operation does not succeed immediately then the calling RTOS task will be held in the Blocked state (so that other tasks can execute) until either the connect request is successful, or the timeout expires. 
 So please remove from your code first this while loop which seems that you do not need , since the function you have for ping requests is commented. And try to put the connect process in a retry loop until the result you get from the connect API is 0. In your code res=0. 
 
 Hope it helps. 
 Best Regards, 
 IK_Renesas

IK_Renesas · Answer

Hello sir, 
 I have implemented in the past a demo for a TCP client for RA6M3 board and now I added to this the functionality to receive also messages from the TCP server. 
 My implementation is different than yours I have a seperate function for creating the TCP socket and connecting to a remote TCP server. And this function is not inside the while(true) loop as in your code. 
 It is called once, I haven't added any delays just added a number of retries to connect to the TCP server in case the first attempt fails.

As you can see I am both able to send and receive messages from both sides as soon as the connection between TCP client and server is done.

Find the example code here: 
 4370.tcp_client_ra6m3.zip 
 Hope it helps. 
 
 Best Regards, 
 IK_Renesas