American Power Conversion MatrixTM UPS - Manual (Page 26)

6.4 Computer Interface Port
The computer interface port is diagrammed below for your reference. 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.
n Outputs at pins 3, 5 and 6 are actually 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 non-inductive
load of 25 mAdc. Use only Pin 4 as the common.
n The output at Pin 2 will generate a LO to HI RS-232 level upon transfer of the output load to power
derived from the UPS’s battery. The pin is normally at a LO RS-232 level.
n The UPS will shut down when a HI RS-232 level, sustained for 4.5 s, is applied to Pin 1. The UPS
responds to this signal, following a delay, only during utility failures (load is operating from the
UPS’s internal power source).
n 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.