W5300 keep alive

We use w5300 chip in our project and want to activate the keep alive time register, or the SEND_KEEP.

In our system, settings register Sn_KPALVTR to 1 to activate sending keep alive packet once in 5sec.
After the w5300 had TCP connection and it is in SOCK_ESTABLISHED mode, only after one packet is transmitted it activates the KA packets.
It is not activating after receiving packets without sending.
In your DS said that:
“KA packet can be transmitted after Sn_SSR is changed to SOCK_ESTABLISHED and more
than one time DATA packet transmitting or receiving.”
Is it possible to active the w5300 to send KA packets after receiving data without sending?



I’m peter employee of wiznet.
Unfortunately, It’s impossible to send KA packets without tcp sending.