Hi, Not strictly PLC but I'm designing a safety PLC system using Siemens S7-1500F, does anyone know what the correct IEC graphical symbol or legend is for a two hand start pushbutton? I've searched everywhere to no avail, I need it for the documentation.
I need to make a shift register which is approximatly 400 bits long in an s7-1200 PLC. The input bit (left hand) of the shift register needs to load with either 0 or 1 according to the state of a digital input. Another digital input causes the entire register to shift 1 bit to the right. Operation speed is quite slow, bit shift occuring at about 1Hz. I need to be able to look at the value of 8 different bits at specific points along the register.