When we press START, it starts motor M1 & opens the C1 which passes coal from storage tank to primary crusher. When level ML1, reaches O: 0/1 wills ON, it starts motor M2 & M3, which crushes coal in small part & pass to the secondary crusher. When level ML2 reaches O: 0/2 wills ON, it starts coal mill, starting motors M4, M5, M6 & M7. Example 9