This is due to the proprietary pinout of apc smart ups serial cables.
Apc smart ups serial cable pinout.
Do not connect the serial cable if it is.
The documented pinout looks like a simple null modem cable swapping the tx and rx pins.
Should work with apc powerchute or apcupsd ups server for linux.
The jack in the ups is actually a 10 pin rj45 rj50.
Apc smart ups db9 cable apc part 940 0024c 940 0024b 940 0024d or 940 1524 black cable.
Pinouts ups devices apc pinouts.
Apc rack mount smart signalling db9 cable pinout apc usb cable schematic cable pinout.
Pinouts devices connectors.
Smart ups 4 5g serial smt750 smt1000 smt1500 smt2200 smt3000.
Pinout of apc smart ups cable and layout of 9 pin d sub male connector and 9 pin d sub female connectorapc part 940 0024c 940 0024b 940 0024d or 940 1524 black cable.
Ups communications cable smart signalling 15 4 5m db9 to rj45 ups cables that provide dedicated connections between apc upss and desktops workstations and servers ap940 1525a.
Should work with apc powerchute or apcupsd ups server for linux.
Smart ups 5g serial smx750 smx1000 smx1500 smx3000.
Apc serial cables will always have part number clearly marked on the connector end of the cable.
However you can just as easily use a 8 pin rj45 connector which is more standard.
Compatible with most apc upss that have a db9 serial port.
Pinout of apc smart ups interface port and layout of 9 pin d sub male connectormay be used for building your own cable.
Always make sure a proper apc serial cable is being used.
Black apc 940 0024c smart signalling ups cable wiring diagram this information is verified and tested to be 100 correct.
Compatible with most apc upss that have a db9 serial port.