APC UPS control system manual BackOffice ES, BackUPS ES and CS in Serial mode with Cable 940-0128A

BackOffice ES:

The BackUPS ES has a straight through serial cable with no identification on the plugs. To make it work with apcupsd, specify the UPSCABLE 940-0119Aand UPSTYPE backups. The equivalent of cable 940-0119A is done on a PCB inside the unit. Thanks to William Stock for supplying us with the information about the straight through cable, the PCB, and the following diagram:

computer			-----------		BackUPS-ES -----------------
DB9-M			DB-9F
pin	signal		pin
4	DSR	->	4 --	+
					diode	resistor
6	DTR	->	6 --	+----	>----	/\/\/\	---	o	kill power
1	DCD	<-	1 --	+
2	RxD	<-	2 --	+----------------			+--	o	low battery
7	RTS	->	7 --------		+--	/\/\/\--	+
					+--	/\/\/\--	+
8	RI	<-	8 --	+----------------			+--	o	on battery
9	CTS	<-	9 --	+
5	GND	---	5 ----------------------					o	ground
3	TxD		3	nc

BackUPS ES and CS in Serial mode with Cable 940-0128A:

Though these UPSes are USB UPSes, APC supplies a serial cable (typically with a green DB9 F connector) that has 940-0128A stamped into one side of the plastic serial port connector. The other end of the cable is a 10 pin RJ45 connector that plugs into the UPS (thanks to Dean Waldow for sending me a cable!). Apcupsd version 3.8.5 and later supports this cable when specified as UPSCABLE 940-0128Aand UPSTYPE backups. However, running in this mode much of the information that would be available in USB mode is lost. In addition, when apcupsd attempts to instruct the UPS to kill the power, it begins cycling about 4 times a second between battery and line.

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