Run Core Using LAN Only

Hi guys,
Is it possible to run Spark core on lan without connecting to wan network
and can call function digital read , digital write ?

YES. Once the Core is programmed, it can run processes without being connected to the internet.
In fact, I use the command Spark.sleep(99999); if I don’t need to access internet. Just make sure there is several seconds delay [ in setup() ] when the reset button is pressed to allow for the next code flashing.

What you’ll need to do is set the system mode to MANUAL and then simply don’t activate the cloud connection. See the docs here:

http://docs.particle.io/photon/firmware/#system-system-modes