ST modules
Connection to bus via bus adapter; switchboard modules in IP 20 housing. Predecessor of the Inline range; lower level of modularity (16, 32 DIO).
Fieldline modules
Direct connection to bus, I/O modules in plastic housing to IP 67. Marked reduction in installation and project costs. Pre-cut cables with M12 connectors in straight and right-angled design. Modules can be networked with various bus types (INTERBUS, PROFIBUS DP, CANopen, DeviceNET); DI, DO and DIO only; no analog modules.