CLICK PLC CPU, 8 DC in / 6 relay out, with Real Time Clock / Calendar and battery-backed memory, requires a 24VDC power supply, 8k steps program memory, 6.4k words data memory, Relay Ladder Logic programming; built-in RS-232C programming port, additional RS-232C ASCII or Modbus RTU communications port (configurable up to 115.2 kbaud), 3-wire RS-485 networking port for ASCII or Modbus RTU communications. Discrete Inputs: 8 DC inputs, 24VDC sink/source, 2 isolated commons. Discrete Outputs: 6 relay outputs, 6-240 VAC / 6-27 VDC Form A (SPST) relays, 1.0A/point, 2 isolated commons. Removable I/O terminal block. Battery for memory sold separately (D2-BAT-1). Requires CLICK programming software v1.20 or later and CLICK CPU firmware v1.20 or later.