I/O system NX I/O Bus Type of module Digital I/O Number of digital inputs 4 Digital input type NPN Permitted voltage at input 15-28.8 V OFF/ON delay 0-0.0001 ms Number of digital outputs 0 Digital output type None Short-circuit protected outputs Connection method 2-wire, 3-wire Signal processing High speed, Timestamp IO-Link master I/O connection type Push-in Number of I/O connectors 1 Detachable I/O connector Suitable for safety functions SIL according to IEC 61508 None Communication port(s) None Number of IOV (V+) terminals 4 Number of IOG (V-) terminals 4 Number of COM terminals 0 Degree of protection (IP) IP20 Product Height (unpacked) 104.5 mm Product Width (unpacked) 12 mm Product Depth (unpacked) 80.1 mm Product Weight (unpacked) 65 g