48 • Linux Fieldbus Coupler 750-860Selector SwitchWAGO-I/O-SYSTEM 750Linux Fieldbus Coupler3.6 Selector SwitchThe selector switch is located behind the cover flap.Selector switchFig. 3-6: Selector switch g01xx10dThe selector switch is a pressure switch/slide switch with three differentpositions and one pressure switch function. You can control the behavior ofthe serial interface or the boot process via the selector switch.The number of operations of the selector switch complies with EN61131T2.Selector switch FunctionUpper position The Linux coupler is started with a Linux console on theserial interface (38400-8-N-1- NoFlowControl).Middle position WAGO program IO update is supported.Lower position Linux coupler starts Bootstrap Loader (BSL).Pressed down(e.g. using a screwdriver)Hardware resetThe boot loader analyzes the position of the selector switch, changes the Linuxkernel start parameters and adds or deletes the wago_console=yes parameter.The serial interface driver and the boot code in the /etc/startwago file evaluatethe start parameter. In the /etc/startwago file it will be decided whether or notto start the /bin/io-check or the /bin/getty program.
