ABB WATCHDOG & I/O ABB NWIO-01 64168533 Watchdog & I/O Module Watchdog and digital I/O module for ABB control applications requiring monitored operation and relay-based digital I/O. Type: NWIO-01 Product ID: 64168533 Function: Watchdog & I/O Product Function ABB NWIO-01 combines digital I/O with watchdog supervision. Its watchdog circuit monitors the operation of the associated control environment and can control the DO2 relay output when watchdog operation is enabled.