TCP Keepalive

Hi All,

I have try to use TCP KEEPALIVE feature in RL-ARM Version 4.13, but it does not work. I have take a look on the Release Notes for RL-ARM(Version 4.13, as shown below), it is stated the TCPnet have add in the TCP KEEPALIVE processing.

Below is my tcp_get_socket function initialization, but it always return a value 0.
socket = tcp_get_socket((TCP_TYPE_SERVER | 0x10), 0, 1000, TCP_Server_Callback);

I have stucked with this issue for a long time. Any guys have use it before, can provide me any advise.

Thanks a lot !!!!

RL-ARM Version 4.13
[RTX - Enhancements]
Added: RTX configuration for ROHM BU1511KV2 device. Preconfigured RTX_Blinky example for the ROHM BU1511KV2-EB evaluation board can be found in ..\ARM\Boards\ROHM\BU1511KV2 folder.
Added: RTX Kernel support for Cortex-R4 architecture. An RTX_Blinky example for the Keil MCBTMS570 board can be found in ..\ARM\Boards\Keil\MCBTMS570 folder.
Added: big endian RTX libraries for Cortex-M0, Cortex-M1, Cortex-M3 and Cortex-M4.
[RTX - Problems Solved]
Corrected: a problem in isr_mbx_receive() function for Cortex-M library. If sending task was suspended on a full mailbox, a message was lost.

[TCPnet - Enhancements]
Added: processing of TCP keep-alive packets.
Enhanced: PPP debug messages.
Added: a library function snmp_set_community() to change a SNMP community at runtime.

[TCPnet - Problems Solved]
Corrected: receive filtering of subnet's broadcast to accept only local subnet's broadcasts.
Extended: filename length limitation in WEB Server for fopen request from 40 to 120 characters.
Corrected: a connection fail problem in PPP client. Some PPP servers require LCP MRU option. If this option is not accepted, PPP connection fails.
Corrected: a connection fail problem in PPP server. PC clients were unable to connect at low speed (9600 baud) in high latency (2 sec) GPRS networks.
Corrected: extended character handling in Web server CGI scripts for Windows (ANSI) 8-bit code pages.