American Power Conversion 400 user manual Computer Interface port

6.0 UPS Monitoring

6.4 Computer Interface port

The Computer Interface port is diagramed below. Those with technical abilities wishing to use this port in a special application should be aware of the following limitations and capabilities of the interface.

■Outputs at Pins 3, 5, and 6 are open collector outputs which must be pulled up to a common referenced supply no greater than +40 Vdc. The transistors are capable of a maximum noninductive load of 25 mAdc. Use only Pin 4 as the common.

■The output at Pin 2 generates a low-to-high RS-232 level upon transfer of the output load to UPS battery power. The pin is normally at a low RS-232 level.

■The UPS shuts down when a high RS-232 level is applied to Pin 1 for 4.5 seconds. The UPS responds to this signal, after a delay, only during on- battery operation.

■An unregulated +24 Vdc appears at Pin 8 of the interface port whenever the UPS is powered. The supply is limited to 40 mAdc maximum.

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