ABB Bailey NWIO-01 Watchdog I/O Module 100% Genuine New

NWIO-01 Watchdog & I/O is a digital I/O option unit. It contains a watchdog logic for supervising the operation of the AC 800M and the CI858 software. The unit has two digital inputs (24 VDC or 115/230 VAC) and two digital outputs. Using a slide switch on the top of the unit, the watchdog logic can be connected to control the state of the digital output DO2.

The watchdog supervises the following operations of the CI858:

• Functioning of the CI858 application program.
• Communication over the dual-port memory.
• Functioning of the CI858 operative system.
• Communication on the optical I/O ring

The factory setting of the watchdog time constant is 1 s but it can be shortened to 0.2 s with jumper X1 inside the unit:

• X1, pins 1-2 = 0.2 s
• X1, pins 3-4 = 1 s

The cycle time of the oscillator is 2 times the execution interval of the NWIO1DO. It must be fast enough compared with the time constant selection in the NWIO-01 unit:

For a time constant of 1 s:

• Execution interval of the task < 100 ms
• Cycle time of the oscillator < 200 ms

For a time constant of 0.2 s:

• Execution interval of the task < 20 ms
• Cycle time of the oscillator < 40 ms