Type of Relay Contacts
The UPS must have normally open relay contacts that close during an AC power failure.
No hardware debouncing of this contacts is necessary in hardware because the debauncing is done in software. No external pullup resistor is required on the external AC fail signal.
Recommended UPS Modes
Banyan recommends an on-line mode UPS or a standard mode UPS with a very short transfer time
(less than 2 ms).
Pinout Connections on PC-Based Servers
The following schematic shows the pinout connections from the UPS to a 25-pin, D-shell, PC-compatible parallel printer port on VINES Unlimited and VINES SMP servers.