HMI SL400N;
at IO or setting page, short press this button back to upper stage page and long press this button back to homepage;When setting parameters, press this button discard data setting and return to home page;
at homepage, long press this button indicates controller version information;
When setting parameters, short press this button increase data, long 
Press for quick increase;
at I/O page, press this button to return upper stage page.