The Allen-Bradley / Rockwell Automation 1771-IT 10...60V DC sink (source load) Digital Input Module houses 8 inputs. Operating voltage for 1771IT is 12...27V. Backplane current load is 74mA and off-state current max. is 1.3mA. Wiring arm is the 1771-WA. 1771-IT is compatible with source switching devices, including: dry-contact switches, electro-mechanical transmitters, and panel switching devices.