Redundant Power Inputs

RJ45 (8-pin) to RJ45 (8-pin) Cross-Over Cable Wiring

Switch Port (NIC Port)

RJ45 Connector

(Rx+) Tx+

(Rx-) Tx-

(Tx+) Rx+

(Tx-) Rx-

	Cross-Over Cable
	RJ45 Plug Pin 1
	Cable Wiring
3		1
3		1
6		2
6		2
1		3
1		3
2		6
2		6

Switch Port (NIC Port)

RJ45 Connector

Rx+ (Tx+)

Rx- (Tx-)

Tx+ (Rx+)

Tx- (Rx-)

Both power inputs can be connected simultaneously to live DC power sources. If one power source fails, the other live source acts as a backup, and automatically supplies all of the NI UES-3880’s power needs.

Alarm Contact

The NI UES-3880 has one Alarm Contact located on the top panel. For detailed instructions on how to connect the Alarm Contact power wires to the two middle contacts of the 6-contact terminal block connector, see the Wiring the Alarm Contact section. A typical scenario would be to connect the Fault circuit to a warning light located in the control room. The light can be set up to switch on when a fault is detected.

The Alarm Contact has two terminals that form a Fault circuit for connecting to an alarm system. The two wires attached to the Fault contacts form an open circuit when (1) the NI UES-3880 has lost power from one of the DC power inputs, or (2) one of the ports for which the corresponding PORT ALARM DIP Switch is set to ON is not properly connected.

If neither of these two conditions occurs, the Fault circuit will be closed.

DIP Switch Settings

ONDIP

1 2 3 4 5 6 7 8

ON: Enables the corresponding PORT Alarm. If the port’s link fails, the relay will form an open circuit and the fault LED will light up.

Off: Disables the corresponding PORT Alarm. The relay will form a closed circuit and the Fault LED will never light up.

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